I agree it's a good way to take responsibility, but I can see it getting out of control if you don't leave people the opportunity to learn. I've had a problem going too far this way and creating a team where, no matter how much a I simplified and documented, no one could fix build problems but me. I've since backed off a bit on later projects and made sure people get their hands dirty early so they don't feel like I "own" the build (or an app or module or whatever).
Great advice. Lending a hand on subjects which you know you can just do better can save a lot of time, and you can avoid frustration by just communicating that you're taking the responsibility.