I agree with a lot of what was just posted, I just wanted to add that players are fairly smart, which makes it challenging for designers are multiple levels.

I would definitely agree that communication is not easy and players (just as forum posters!) may be well intentioned however a great deal may be lost via using just the written word. However if you want to look at the challenges of game design - I would point you to CC- "Good job" is so innocuous, isn't it? Perhaps not so much when it's spammed over and over though. So much for that design.

You are speculating about someone who is going to be called out by someone because unlike any other job they may not be able to hypothetically hit 2 buttons (which all healers could do previously, by the way) , in content where they would likely not be required to do that in order to complete it? That's a lot of "IFs".

Whereas in more difficult content, or in solo content, that option could be available for those healers who wanted to make use of available downtime but lacked options?

I don't see the option that you're proposing, what is less than "maintain one dot and use one DPS skill" when you're not healing?