Honestly, I don't see what makes paid mods such a big deal. If you don't like it, you really don't have to do anything of the sort.
Eh. The deal for me is that they've pretty persistently, in most attempts to implement them, just kinda' destroyed or severely damaged whatever content creation community may have existed, or more or less crippled whatever was trying to grow. We have past attempts at the concept and we know pretty solidly it's bad for content creation in general -- possibly the closest thing to an exception is with
strictly cosmetic mods, and even that's iffy depending on how much the work involve interacts with other portions of the game engine.
Specific modders may come out better, but the mod scene for any particular game tends to come out notably worse, and modders on the
net tend to suffer from it since a lot of what makes it easier for people to get into modding (other mods, that are largely open to perusal, and a community of modders that don't have terribly strong reasons to keep people from entering the metaphorical market) gets stuck behind paywalls. You end up with less mods and less modders, and in general because of that, even if the fewer ones have more motivation the quality of work on the whole drops; mod communities live and die based on how many people are working in them, and what's coming out of that shakespearian typing monkey environment. Usually, with these kinds of efforts, one superlative creator is still going to be outdone by a couple dozen mediocre one banging their heads together and gluing whatever falls out into pretty shapes. Problem with paywalls is it does a lot to depress or prevent those couple dozen's communal headbanging (by locking inspirational code behind costs, by adding heaps of legal concerns, by hard spiking elitism issues, and so on, and so forth), and that is very much something the players and most mod creators don't want at
all.
... we also have a very simple and much less troublesome way of giving modders some monetary appreciation, without nearly as much of mess as comes with actual paywalls: We call it a donate button.
So what you have is something that we've had demonstrated repeatedly is bad for, at least, both players and mod makers, and we have an alternative that incentivises pretty much everything that something does, without nearly as many of the problems associated with it. Means when someone tries to implement the former, people tend to view it as pretty sketchy. You have someone that's coming in and trying to damage a mod community, when they have an obvious alternative that will
not do that, at the absolute least to nearly the same extent.