Earlier quoted context omitted.
Yes, it's your right to block the EU users. But, if you want their money (and that's up to you to decide), you have to obey to their law, nothing new here.
It's not their money, it's if you store or process personal data about individuals in the European Economic Area (slightly larger than the EU). If you're running a Chinese site aimed at Chinese you're good. If you're running an Indonesian site aimed at Germans you need to honour the GDPR.
For starters, if you don't take payment and aren't in the EU, EU enforcement power is going to be extraordinarily limited. And even if you do require payment, if you don't have a physical nexus in the EU, it's unclear what exactly the EU can do?
I think the GDPR was basically aimed at some of the scummier adtech practices and businesses like Facebook, and for those, it will be very enforceable.