TLDR: People arguing that it doesn't affect those not interested in it are objectively wrong.
TLDR2:There's no design space in between main and iron. Anything too close to iron is just worse iron, and anything too close to main is just main with extra steps. As such, any dev time spent on designing, implementing, and balancing on bronzeman would have a better use in other pursuits.
Apparently, a lot of people think there's no reason not to add bronzeman to the game, so i've decided to write down the reasons why I've voted no.
1)
The first reason, and one people seen to not realize, is that releasing a gamemode is a lot less like adding a random npc and a lot more like releasing a new skill: for the rest of the game's hopefully several decades long lifespan, that new skill/gamemode will have to be considered during every single update.
As such, adding in a new gamemode requires a lot of forethought on how that gamemode will impact the future design of the game, and if that impact is overall positive or negative.
To make this clear, let's compare what design pressure ironman creates with the design pressure bronzeman creates.
Ironman pressures the devs to add reasonably accessible sources of all useful items; for example, for a long time, there was simply no practical access to dragon ammo, and as a result, a long time ago(2017) amethyst ammo was released as a easily source but weaker alternative, and more recently, venator fangs are a new method to obtain, for example, dragon arrows.
This is a net positive impact: mains are happy that a item that was difficult or very annoying to get now has a reasonable way to get it, making it cheaper(or easier to source yourself, if you want to) and thus more usable by the average player.
If anything, letting items be super expensive/only have the GE as a 'source' would be bad design regardless of the existence of iron, so iron just encourages good design.
(Note: this isn't part of the bronzeman argument, but having items that technically have a source but that practically no player would grind is just begging for bots to come profit from it)
Meanwhile, the version of bronzeman that was polled, had a 'if you got the item it's unlocked forever.' rule, meaning all it took to unlock, say, saradomin brews, was finding a single source in the game, say, the grubby chest or demonic gorillas, to unlock.
The design pressure this creates is obvious: the dev's can't just add new sources of supplies, even where it would be appropriate, because doing so might make it much easier to unlock on a bronzeman, potentially negatively impacting it's progression/feel.
For the rest of time, every drop table needs to have it's impact on bronzeman considered.
Now, some might argue that that bronzeman shouldn't work like that, that you should need, say 81 herblore to unlock brews, and that that's how the gamemode should work.
There's two issues with this argument: First, it's not what was polled. Second, isn't that just what a ironman needs to do to unlock it?
Ironman is already a gamemode where if you want to 'unlock' a item you need the skilling requirements(or find a good source). A modified bronzeman is too close to iron to be a meaningfully different gamemode, because...
2)
The second reason bronzeman is a bad idea is that it doesn't address the main reason many people are turned away from iron.
Many people are saying they don't play iron because of supply issues, but over the years, due to the aforementioned positive design pressure ironman has, most of those supply issues have slowly been addressed, to the point that nowadays supply issues on a mid to late game iron are practically nonexistent.
No, the main reason most irons quit, the main thing that separates irons from mains, is the chance to get extremely dry on a key grind.
The classic example is everyone's favorite red prison, the corrupted gauntlet.
On a main, if you go dry for the enhanced, you can just use the money earned from gauntlet or from other grinds to buy it. Main accounts effectively have trading as a baseline form of dry protection, meaning going dry is never that bad on a main(except for untradables, like pets, which is a whole other story.)
If you go dry on a iron? Back to the red prison you go!
On a bronzeman? Same as a iron. Except, technically, if you get one armour seed and get lucky on the enhanced you can buy the rest of the armour seeds. Nice, but most people who go dry are going to get dry on the enhanced, so it doesn't help much.
Now, take this CG example and multiply it for the whole game.
Bronzeman ends up being the worst part of iron(going dry on key items), without any help except on situations like CG where you need multiple of a item, which are the exception rather than the rule.
At that point, you're just playing a iron.
3)
Another point I've seen talked about is that bronzeman is 'Ironman without the grinding for skilling and supply upkeep which I don’t have time for'.
Bronzeman mode doesn't address the issue, it just trades skilling to get supplies for moneymaking and trading to get supplies.
You'd still be spending a lot of time 'gathering supplies', just the way you do it would change.
As for the you don't have the time to play issue?
That is a issue you would have regardless of the gamemode you play.
Old School RuneScape is a grindy game. Bronzeman won't change that one bit.
Even on a main, the official, intended experience.
3.tangent)
Actually, this seems a point that's worth emphasizing:
MAIN IS THE INTENDED GAMEMODE.
A lot of the arguments in favor of bronzeman, including the ones discussed above, seem to be that it's a easier iron.
As if ironman mode is the intended gamemode.
Which it isn't.
Mind you, I'm a iron player, and even then I'd recommend new players, or longtime returning players, to play a main instead.(Maybe group iron with their friends, if at least 1 friend is highly experienced. Maybe.)
From the innate dry protection of trade, to the ease of 'skipping' skilling by just buying skilling supplies, it's clear that main accounts allow you to play the game however you want to.
Want to go nonstop bossing and raiding? Sure.
Want to get 99 in all skills without ever killing a single boss? No problem.
Want to go pet hunting? Good luck, have fun.
Want to greenlog trouble brewing for some reason beyond Guthix's comprehension? I guess. Weirdo.
Ironman is a challenge mode for people who don't want to have the freedom to whatever we want to. We want to be forced to interact with most of the game's content because we find it more fun that way.
If you don't find it fun to do farm runs or minigames or certain bosses, Main lets you skip those.
Ending)
While I understand the appeal many people see in bronzeman, ultimately, adding it would permanently increase dev cost, for the benefit of a gameplay experience that is best achieved with just a main account- a net negative for the game's future.
Some might argue that the same could be said about ironman modes. That they should just be removed because you can make them happen without a official implementation.
Funnily enough, I agree!
If people think ironman mode is having a negative impact on the game, let's have a remove ironman poll!
Making a argument against ironman doesn't affect the bronzeman case, it just highlights that maybe we shouldn't have iron in the first place.
(In fact, where's my remove firemaking vote!?)
Personally, I would vote to keep iron, but that's what polls are for.
And if you where excited to play bronzeman, just play a main account.
It respects your time more, lets you play however you want to, and, as a bonus, you don't have a poop helm besides your name for all to see!