Well first of all, heel hooks are still taught in jiu-jitsu and used in no-gi advanced competitions. Rick Macauley, Lloyd Irvin, and many others use them a lot. For gi competitions,
They aren't being hypocritical. They still allow most leg locks in gi at black belt. i.e. The only competition rank which matters to Renzo and the Gracie clan. The career enders - neck cranks and twisting leg locks - are illegal there. Surely you can get behind having those limited. In no-gi competitions, twisting leg locks are often still legal. It is safer in no-gi because shorts can't get caught up in the lock. There are sensible limits like for career and life threatening situations - and gi and no-gi are two different situations.
Renzo said he disagreed with Kano, but that doesn't mean he doesn't have a limit (sorry for the double negative). Do you want BJJ competitions to include pankration-style strikes as well? After all, they are usually less dangerous than heel hooks, slams, or neck cranks. What about just MMA? Or old-school vale-tudo. Or anything goes? Where do you draw the line?