And these same people who don't have the gear yet to make heroics or even non-heroics trivial probably also don't have the gear to blow mana on casting a heal every button push. You're running a druid healer, you're supposed to roll hots and WG.

A lot of other people are running Shaman or Priest, even Holydins. Hell, some people don't even have dedicated healers, they rely on DPS heals like Rets with AoW procs or all Ele shammies with LHW and CH. Group healing requires varied targeting for certain classes and Tank +4DPS setups require more flexibility so as to not step all over DPS output when heals may be needed. 1 button healing is not the most effective way to deal with boxing for many people. Multiple healing configurations make things a lot easier for some people, not more complicated.