Well they do. If they didn't care and weren't planning to comply with EU rulings, they wouldn't have put a block in place to avoid processing data of EU citizens.

(Also, 90% of complying with GDPR is just ethics -- tell if you sell data to third parties, ask consent if you want to do nonessential processing, etc. -- and 10% is adding boilerplate text like reiterating your rights. But that's a bit of a separate discussion, I just feel like most people are not aware of this when starting these discussions and it might be good to know when talking about the topic.)