Mods as in peripherals? They aren't as much of a thing, but still exist for specific games.
Mods are modifications of the game.
Resource Modifications (frequent), Code Modifications (harder), Memory Modifications (maybe not considered "modding" but "cheating").
I don't see the correlation to be honest.
(Not focused on you)
Easy mods like extra costumes, extra hats, go in direct competition with in-game selling of extra costumes, extra hats.
Yes, single-player games
usually don't make you pay for those small visual extras (unless it's in the form of bonuses for a bigger DLC). So they should become moddable without problem.
[against OP's argument in case where there are no games selling hats for singleplayer content]
It's mostly a thing for multiplayer games where there are social strings attached to your appearance, that paid microtransaction exist for things that are easily added as a mod. But it's not at the same time since modding your game's visuals in multiplayer doesn't always affect the other games (you cannot show people an item that doesn't exist in the game).
[against OP's argument in case where visual mods don't have an impact in multiplayer]
Devs could be more worried about cheat mods in a multiplayer environment, depending on how the game was coded, and if there is a progression system attached to the online.
[neutral to OP's argument, bringing an alternative reason why mods are seen badly by plaform holder]
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Mods are not limited to visual mods. On mobile, you pay for microtransactions in single-player games (with "multiplayer" leaderboards tacked on) that are not only cosmetic, but also make the game easier/unlock functionalities. (Usually prey on less knowledgeable players.) Those levers could easily be Switched by mods. So there's another incompatibility for games that are both on mobile and consoles.
[for OP's argument in games that have mobile-like microtransactions on singleplayer console games]
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So your argument is with mods, users could create the content they're being made to pay for instead? But there are PC games with both mod support and mtx. People will pay for official content regardless, if only for the perceived superior quality
This is true for new zones etc. which [1] require a lot of work to get polished [2] are unique creations:
two different stories are not a replacement of eachother.
This is not true for costumes/items. For example, two costumes on the same concept or that make the same reference are
a replacement of eachother.
This is true for content that requires server-side authentication to use (you download the new campaign, you unlock an item in an online mode).
This is not true for content that is locked in the game data where a switch could be flipped by a mod to access the exact same content/feature. Or for things that take so little modifications to the base code that a mod could replicate it
exactly.
[for OP's argument since there are content where mods are a good replacement for something the devs would like to sell you trough microtransactions]
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The user has a lot of control over the system when they play on PC. Mods are easily available so devs/pubs have to live with them... unless they do something to protect the game's code, like, code anti-tamper, and
DRM. Which is not rare.
The prevalence of anti-tamper like Denuvo that hampers code modding could be an indication that if they could, a lot of big-time developers/publishers would also like to limit the possibility of modding on the PC.
[neutral to OP's argument, show that the "on consoles" part of the argument is separate from the "micro-transactions" part]
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Why else would mods be reviled by platform holders? It's not like artistic integrity is that high in their priority list.
[discrediting counter-argument of artistic integrity]
- It must be a monetary reason, and the only thing mods could be a replacement of are not-server-checked small visual content often sold in microtransactions, or not-server-checked small gameplay improvements that either reduce playtime or opportunity for the player to pay more. [highlighting OP's point]
- It must be a branding reason, as modified copies of the game could give the wrong impression of the game (in term of nudity, violence, content). [alternative to OP's point] This goes beyond artistic integrity, it's marketing, sales potential.
- It must be a technical reason. Not that they are making modding on consoles hard, but that it takes work to make it easy, to give the tools to access the files. Money not spent on making more money. [alternative to OP's point]
- It must be for non-reasonned cultural reasons. That they are not thinking of mods as a good thing for games, and haven't questionned the habit of locking down their consoles. [alternative to OP's point]
- It must be a side effect of their security measures for games. After all, if an user can modify freely a game, wouldn't they just be able to just insert pirated code? [alternative to OP's point]