Don't just whine about it, DO something about it! What people like to forget is that we too have our own methods of "retaliation". Not convinced that you should sign this? I got some reasons for you!
Modding, in it's own right, is a reward in itself. If you wanna make money off it you might as well make cosmetics for TF2 or DOTA or hell, try to get a job in the gaming industry whether it be indie or professional.
Of course people also make mods to just make themselves more widely known and "E-Famous", but you're not gonna win E-Fame points by making people pay up.
Monetisation brings out the worst in people, just look at Free2Play games with a TON of locked content. Imagine that, expect with community made mods that aren't as good, but are around the same price range.
A few mods are already switching to Steam Workshop P2P but still have free versions on the Nexus. However, the free versions will not be supported with new updates in the future unlike the P2P mods. This divide in versions will probably hinder mods that require other mods to work on top of eachother.
Bethesda and Valve get 75% of the already meager profits. If you wanna help a modder "make a living off their work", then regular donations would be WAY better. And if the modder had any thought of money prior to this, they would have made something like a Patreon instead.
Totalbiscuit has not made a Skyrim mod and lot of people who approve of the monetisation are NOT modders at all. So their modding community insight is not the most "one-on-one".
Normally I don't do things like this, but this issue is touching me deep down within my balls and the fact that I'm getting messages from a lot of people about it just reinforces it.