I'm the same, I've seen some of my stuff pop up in the weirdest places and I was ok with it. But I understand and respect that people who published code under restrictive licenses may have a problem. The GPL is absolutely "NOT-a-free-gift" license, in both wording and spirit.

If someone published something as MIT and doesn't like it being used for LLM training, yeah that person can only blame themselves.

For GPL, it all depends if you consider a LLM "derivative software" of the GPL code it was trained on. It's fair to have an opinion on that either way, but I don't think it's fair to treat that opinion as the obvious truth. The same applies to art, a lot of it is visible on the Internet but that doesn't make it "a gift".