I'd like to say this is surprising but that would be a lie. The instant I saw the announcement, the first thing that popped into my head was "this will not end well". Gamers have proven themselves, time and time again, to be the most entitled and selfish group of people I've ever seen, and this is just one more example.
How *dare* anyone have the audacity to suggest that maybe, just maybe if they spent a lot of time and effort making something they should get a few bucks for it. No, they DEMAND everything be given to them for free, or for "donations" (which we all know is codeword for someone else gives the author money, maybe, if they are lucky). I see people saying they won't pay even a single penny for a mod - they are essentially saying that the modders hard work is worth nothing to them. How insulting is that? I actually saw one person post saying the modders were leeches.... how can you lack so much self awareness that you would post that?
Is the system perfect? No. Stealing mods and posting them as your own is something they have to figure out how to avoid. 25% cut to the modder also might not quite be fair (though I think it's not quite as bad as it sounds since the modder is getting access the the IP, free marketing, sales processing, hosting etc). Does the gaming community discuss it in a rational, reasoned way? ha ha no, of course not - they throw a damn fit because they feel entitled to other people's work for free.
The whole thing leaves me disgusted, but sadly not surprised at all.