In principle I'm all for modders being able to monetise their work if they so wish - they've brought a lot of extra enjoyment to many games I've played over the years. However, in reality this has epic potential to turn into an ugly mess.
I've done modding in the past myself on a number of games, never anything too grand though. Saying that, the mods I've created have often made small but significant changes to an underlying core mechanic and have gone on to be incorporated into numerous other mods. I was happy with that, even though many (doubtless through ignorance) didn't realise the origins of a core feature of what they now considered their mod, was actually my mod. But hey, everyone did this for fun and for free so it's all good.
So, with money being on the table now, even if it's only 25% of the asking price, the entire dynamic changes. If someone has created a mod that becomes popular and they make good money from it, as is their right, that's all well and good. What about the guys who wrote the smaller mods that provided the foundation though? How do they get their "cut" if they choose to pursue it? How does one assign value to a "small" mod used by a "large" mod, without which the larger mod could simply not exist? Gonna get messy!
Personally, while a little extra income is always welcome, I doubt I'd ever want to monetise any of the things I ever did. Larger mods, where whole teams of people are working on something sure, however then we get the issue I mention above with many smaller mods included along with tools to facilitate certain feature etc.
Also, and likely most significant of course, is that we're all used to mods being free and adding value to the game. Now they'll potentially start to feel like DLC or (urgh) micro-transactions when lots of "little but good" mods appear as separate items, that might have once been bundled together - yes, I'm talking about people trying to maximise income by splitting things over several mods instead...I have a suspicious mind lol. I know it's NOT on the workshop currently, but what if something like SKSE became a paid for download? I'd have to buy it as it's a prerequisite of many of my mods. Thankfully it's its own download and not included in other mods, so does not fall foul of my earlier point, but equally it's interesting due to SKSE near essential nature. Thinking on it, what about all the "unofficial" patches? They're pretty much essential too, and fix tens of thousands (yes, really) of issues never addressed by the devs after they (it seems) abandoned Skyrim somewhat prematurely, one assumes due to the over-spend getting the PS3 version working.
Anyway, interesting times for modders ahead. Some good opportunities for people to make some money from their hobby, but also plenty of opportunity for a total poo storm of in-fighting as people chase their "cut". My slightly jaded mind imagines something like a popular mod team being harassed by ex-members or contributors for their cut once something goes big - sorta fair enough as if the end product has value, so did their time on the project, even if they no longer contribute...
Be interesting to see how this develops.
Scoob.