Why is the healer class basically a one spell dps class?

[Dalvy]

This question is a little complicated.. The truth is that it’s this way now for many reasons; it has been a reaction to player complaints, a result of unpopular design choices, a change from mechanics reworks, and a reduction to button bloat.

[..]

This post is the sum of all of our complaints over these past seven years. . .

WHM has been hit by the nerf bat so many times, had their unique healing skills taken away, given to other classes, that there was a period of time where nobody took them.

SCH used to be "the DPS healer" only to be whittled down into a discount Glare spammer, minus our unique fairy skills, minus our ability to spread dots, and for the second time, this class is being threatened by another Shield healer.

AST is a rollercoaster and a half, being nearly unplayable for a good chunk of SHB, besides the fact that Square took away the most unique support mechanic I've ever seen--their original card buff system

What undue nerfs will we see happen to Sage, all in the name of their "healers need to heal" homogenization philosophy?