In two words - cultural differences. Most NA fans wouldn't watch anything outside of WWE or AEW. and Asian fans wouldn't watch anything outside of NJPW or NOAH. It's not for them. NA fans like gimmicks, characters and storylines - sports entertainment. Japanese like workrate, good matches, and a realistic approach. Pro wrestling as a sport. Anime does not have an equivalent in NA - you either watch anime or you don't. They are also not as mainstream as people think, despite the fact it has gotten more popular in recent years.
