"Paid mods"
Stopped reading there. I'm not paying a cent for any mods.
There are three fields of argument in favour of paid mods. They are all wrong.
1. Modders deserve money for their work
Some modders may believe they deserve money for their work, and some consumers also, but these are inherently subjective judgments. The market will determine who is right. Currently, the state of the market does not support that assertion. There is no normative consensus that modders deserve money for their work, which necessarily means that there is normative consensus that they do not.
2. It will lead to better-quality mods
How? Almost every good major mod is a collaboration effort. How will the revenue be split among the modding team? Let me guess: everyone will magically just get along and share the money and there will literally never ever be a case of a mod team dissolving over sharing out the piddly little 25% left to them? That's crap. Modders will only have to get burned once by collaborative modding to swear off it, and then we'll lose all our great modding teams. And why invest the time, anyway? In Skyrim terms, a small mod (like a new set of armour) might sell for $1, but I don't think you'll see people paying much more than $15 - $20 for even the biggest mod. The biggest mods take a lot longer to make than 15-20 sets of armour I tell you hwat. But what about good minor mods? Well, what about them? They're minor. Tiny little things. Sure, the bigger resolution menu mods for EUIV are useful but I sure as hell wouldn't call them worth my money. In fact, if I couldn't just use that mod I wouldn't be paying someone for it, I'd be yelling and swearing at Paradox for releasing a broken, unusable interface that was too small to read, let alone play on. Good minor mods are mostly things that ought to have been in the game anyway. Those that aren't - well, I certainly don't think they're worth paying for.
3. "I am opposed to paid mods, but what about a donation button?"
Already exists - the "pay what you want" scheme. Unless Valve forces all modders to use it and forces it to be set to zero dollars as the minimum then it's literally pointless. Plus, who the hell donates to modders anyway?
The fact is that modders don't mod for money. How can we tell? Because they don't get paid currently - those that do, don't get paid very much - and yet we still have mods. Tons of mods. Scads of mods. I am modding right now, for free. Modding will literally never be a viable career.
This is the point where I get pointed to the most subscribed mod on the Steam Workshop (Pure Waters) with it's 820,000 subscribers and told "if every one of those subscribers paid a dollar that mod author would be making over $250k a year." This is true, but not every one of those subscribers will pay a dollar. Why? Because if Mr Pure Waters charges a dollar then I replicate his simple work and charge 75c in my own mod. Maybe I even literally just steal his mod and tweak it a bit. Then someone comes along and undercuts me. It's a race to the absolute bottom of what people consider their time worth, and evidently there are enough people who consider their time worth nothing at all to drive prices down to zip. It's not like video games, which require a vastly more massive investment of time and capital - literally anyone who doesn't have Down's can churn out a mod, and the people with Down's can just copy-paste. Sure, the price might stabilize at, like, 10c or 15c, and Mr Pure Waters would still be making $27,000 a year, but the next most subscribed mod has 300,000 less subscribers. And this doesn't even address the fact that people have a maximum limit of money they will spend cumulatively on the Workshop, driving subscription down across all paid mods. The numbers drop off immediately and massively. There will be like 5 or 6 people at the very very top of the modding lottery who make some money, but everyone else gets effectively nothing. Chump change. If you have the time and resources to dick around in front of a computer for a few hours you do not need the $15 you may or may not make in sales.
Which leads me to my final point:
Anyone who thinks modders are going to make anything more than pocket change even if they kept 100% of the revenue is probably not a modder, because modding requires some semblance of intelligence. There is absolutely zero point bringing money into modding at all, other than to let Valve play happy merchant like the greedy, fat, rootless cosmopolitans that they are and make a tidy packet skimming off the top of every 25c sale. It will not help modders. It will not lead to better mods. Anyone who is in support of this is literally worse than Hitler, and that goes for you too Paradox.