I don't know, they may not be as popular as Boards Of Canada, 90s Aphex Twin and *shudders*... Tycho, but they still have a big following, and a lot of love from people outside of the IDM community. Maybe the stuff around the 2000s is where it gets complicated for some regular people, but even then, it's very well received and listened to by many.
I could go all day about how Plaid seems to be more difficult for people to like. It's like they're subtle with how they make their music. You like some stuff, find the rest boring, then later on it all clicks.