Let's be honest. While I'd have no problem with a healing-req increase in general, just look at the situation we're in now while things are supposedly 'easy'. I don't mean to say that as a blanket-insult to Healer-Players of a delicate persuasion, but if it's so hard to throw out a little damage once in a blue-moon when we only need to heal one-third of the time, I'd be curious to see how things go if you're healing 3/4 of the time and only have small opportunity windows for anything else, especially for those of a progressive mindset seeing as Healer DPS is very much a thing there.
I can see how that would sully the Healer-Not-DPS problem and make it less noticeable, though I doubt it is the best option (which isn't implying I have any alternatives in mind).