I don't think it's just Japanese wrestling. Same thing happens to be people who they discover the indies. Heck it happened to me when I was like 12 and watching ECW.
You get use to what mainstream wrestling looks like, and then when you see something that deviates from that it blows your mind. And the little things that matter to mainstream audiences like moves being set up in a believable way, don't really matter to you cause at the end of it they're doing some move you've never seen before.
Watching WWE, at least use to, make you take the basic for granted. That said at least 15 years ago, Japanese wrestling was way better than WWE.