I like Schobel's game for all the reasons you point out. The problem is, that game is usually found in an adequate, non-pro bowl, low salaried left defensive end. I think on other teams, Schobel would be a very valuable player, but with our lack of pass rush he just becomes one of everyone else, which is a good hardworking player that sticks his nose in there.
I like Schobel for his effort and toughness, but we desperately need a pass rusher. We didn't pay him that money to be an average, all around DE. He's got to start making some noise in the sack department. When he does that, he's one of the best DE's in football, but when he doesn't, he becomes a dime-a-dozen player.