Aside from the fact that Frank is consistently voted one of the smartest members of Congress in those polls of Congressional staffers...
Then either the congressional staffers are wrong or members of congress are really stupid. I've seen Barney in person several times, and would describe him as an individual who is perhaps aloof and marches to his own drummer, but he's no genius. He certainly thinks he's a genius, though - every thought that pops into his brain is wisdom worthy of Aristotle, and the most fascinating and original idea on that particular topic that there has ever been.
Hmm... who to trust. People who work with Frank every day or some dude on the Internet who's "seen him in person several times". Difficult choice...