People still do very much know of him. My mother is the person who introduced me to his book. I was showing some interest in science in school when it was presented to me though. Though he's probably waning from "household name" status he's likely still widely known

A lot of the comments on this post are references to the book "surely you're joking Mr Feynman", which was a collection of stories(with a lot of embellishment) told by Feynman.

That is the "sham legacy of Richard Feynman", the fact that most people remember him for stories and not his work