Oh hey, I'm one of those enthusiasts who often recommends paid incremental games!
I think many of the completely unmonetized games are absolutely good enough to warrant some amount of money for their authors. I think there's a lot of reasons why they don't, but part of it is because of the stigma against monetization within the (browser based, not Roblox or mobile parts of the community) incremental games community. I think part of it is valid, due to concerns of games using predatory designs to compel you into spending money, but some of the stigma I think just comes from an unwarranted expectation that incremental games don't deserve to be monetized.
I think that expectation partially comes from how many precedents there are. As you mentioned, there are so many completely unmonetized incremental games out there! That's awesome, and I think it's mostly explained because of how appealing incremental games are for people looking to learn how to design and make any kind of video game (I go in more detail on this point here.
That all said, I think the trend of having more incremental games with upfront price tags and no mtx are fully ethical and allow for incremental games to have higher production values that aren't easily justifiable for unmonetized games. I'll gladly support devs making games in a genre I care so deeply about, and I very rarely regret the amount I've paid (cough CH2 excluded cough).
I think it's perfectly fine for both to co exist. I'll keep buying and playing paid incremental games, and I don't think they detract from how amazing it is that there are so many free, often open source incremental games. I especially want to continue new developers seeing the genre as a good place to first get into how to design and make games, without feeling like by doing so they're lowering the relative value of those paid games. They can all co exist, just continue making things :)