Who said anything about bullrush? Enemy controllers have slides/pushes/pulls/fear effects. Solos basically always have them, especially these days. A four square push/slide/pull+a melee monster moving up next to the Cleric so it has to provoke an OA (minimum) to save the zone is hardly an unusual occurrence (bonus points, use a minion to grab the Cleric: Immobilize... at-will, yeah, that is super rare, and against a Wis/Cha Cleric's weakest NAD). Unless for some strange reason as a DM you are building encounters with zero monster synergy and zero control (in which case any competent party will steamroll your encounters no matter what powers they pick, but that isn't the powers fault).
People only think Consecrated Ground is "overpowered" (ugh) because they don't understand how fragile it is. Even in an original module like Thunderspire Labyrinth, that last fight against the Wizard it was a mixed-blessing. Sure, free healing, but you had to stay grouped up to use it and his AE's really hurt. And that was before the new damage expressions and monsters getting more battlefield control as the default. Now it is completely trivial for the DM to focus the Cleric and move him out of the zone with standard monsters.
Even the new LFR module encounters make a joke out it.
But whatever, I think Consecrated Ground is a decent daily if used in the right situation, and in tons of situations is trivially dealt with just by encounter design. Considering that fact, it should shine when used under the right circumstances.