A lot? They lost seven total games -- two to a 1-seed, one to a 2-seed without their best player and three to 4-seeds. The only game they lost to a non-protected seed all year was against Illinois.
Nonetheless, I don't see how losing those games makes Sullinger overrated. Again, he literally draws a double and sometimes triple team almost everytime he touches the ball. I'd like to see 99.9% of post players in America put up his numbers while having to face that kind of attention every time he touches it.