In some systems the problem is that you can never be guaranteed that the after_commit hook will always run. This is especially true in multi-server systems where the cache, database and front-end servers are separated. The front-end server can update the database and then completely die (power outage, networking, reboot) before talking to the cache.

On the other hand I can see how you would want to drive out bugs instead of just sweeping them under the carpet with auto-healing...