For end game being able to switch to dps is pretty important. Titan HM for instance we currently run it with 3 healers. 2 of which switch to DPS during the heart phase.
For Amdapor keep as a scholar I cleric stance and DPS the entire dungeon letting my faerie do the healing.
The WHM does do the larger focused damage. Stone two has a much higher potency than any SCH skills. however the Scholar has 2 instant cast dots and an instant cast burst + blind. The WHM Dps skills use a lot of mana and cannot be spammed for long but a SCH can more efficiently throw in a little DPS here and there during all boss fights. You will more often see SCH's using dps moves during a fight than a WHM.