That's not true at all. Every major college (and even most small colleges) have at least 2 big men. My D2 school has 3 guys on the roster that are 6'8" or taller. One of my neighbors growing up was 6'11" and started for really good Pitt teams. He got an NBA tryout, but not a serious look. He is playing ball in Europe and I guarandamntee that he'd dominate in rec league. Hundreds of big men every year come out and only a handful make the NBA.