Guys who get sacks warrant big deals and large salaries. Getting a sack is basically just as good as a turnover as more time than not, it's a drive killer.
Add in the actual strips Doom causes that can drastically change the field position and you begin to see why guys like this are so valued across the league.
Stopping the run is fine, sound, logical football. But it doesn't normally have the huge momentum turning effect that getting a sack does.