Just thinking about how SE has confirmed that the 1 DoT/1 Spammable DPS button will continue for WHM, SCH, and AST for the foreseeable future.
So as a possible step toward something marginally better that could eventually be expanded on, why couldn't the one button do more? It would not require learning a second button.
For example, Sage can turn a pew-pew button into a DoT. Summoner can now turn one into very different looking/feeling versions with different summons. You could even do the PvP thing where a single-target rotation is just the same button but three different animations/effects/potencies.
(To give an off-the-cuff possibility, SCH could get a Summoner-ish treatment and better use of Faerie gauge, WHM could use their lily gauge (or not, meh), and AST a secondary use of cards or a PvP-esque single-button rotation with star themes.)
I am not suggesting that more experienced and confident healers who are tired of being Glare/Broil/Malefic Mages give up on lobbying for bigger changes, but I think doing more with 1-1-1-1-1-1-1-1-1-1 play is a start.