The issue is that those cost the airlines a fortune, are a pain to get a claim through, and the costs get passed onto consumers by raising ticket prices.
If only there was an optimal middle ground.
Yeah I agree that there are components of EU261 that are overly onerous on the airlines. That being said, there is definitely some low-hanging fruit that any reasonable person can agree is unacceptable - such as the idea that AA now claims the right to cancel your flight, just shrug their shoulders, and refund your ticket thereby forcing you to go buy a walk-up fare with another airline. That should not be permissible.
And one of the benefits of EU261 already existing is that American regulators/lawmakers would have the benefit of looking at that law and saying "ok we've got years of real-life data to analyze, what works, and what doesn't work with this law"