That's still controlling what users do, and worse, it's what they do with modifications, not even your own original work!! and without even agreeing to a contract of such terms.
It's plagarism if the activity was done under some system that required attribution, or if they misrepresented the change's provenance. neither is the case.
I agree with you on EULA's, they've been rendered useless in some cases and jurisdictions. But at least EULA's have a software prompt that enters their users into an agreement. There is a reason they require you to scroll all the way down and read it before agreeing, it is because how inherently weak they are.
I don't necessarily think EULA's are good, but at least as a user, i actually agreed to them. No one is trying to force me to agree to an EULA simply because EULA.txt exists somewhere in the directory tree of the software. And even if they did and had legal grounds, I still would disagree with any terms I didn't explicitly agree to, or any terms of agreement that are lopsided to the advantage of one side.
copyleft is an attempt at corporate greedy litigious manipulative behavior, except the greedy party doesn't actually want money, they just want control.
