Horrific Visions, arguably of course, is content made mainly for dps specs. However, it is being forced on people who prefer to main on healers and tanks, and who also may not have ever played other specs on their characters and/or who have varying competancy on those other specs. And some say that that is just plain silly. But honestly, you can have levelled your toons by simply running dungeons almost the whole way along, never having had to play other specs. And albeit questing is sometimes rough, it is all doable on healer and tank specs.
Also, there are people who are not keen on reforging their armor to dps specs and back every time they want to do a Horrific Visions (frankly speaking, the lesser Visions as well). Some may not have gear for Horrific Visions. I am in this boat on three healers I main on.
All I can say is, I have wasted a bunch of vessels trying to do this content. I have asked for help from friends who say Horrific Visions for them are easy, and hence have no desire to group up with a healer.
As for tanks, they seem to be having the same problems.
What does this mean for everyone? Well, healers and tanks are being turned off. Some are probably just gonna opt out of healing and tanking, and maybe the game, and maybe for good. That is just going to mean fewer are going to be available when others want to do dungeons and raids, and wait times are going to get even longer.
Thanks Blizzard. Thank you kindly, and see you next expansion, assuming any desire to come back.
Edit: A funny thing in pug raids yesterday… Everyone was wondering why almost all of the healers in the queue were priests! It’s seemingly like some people have put to pasture all of their healers except for their priests–who can do Visions solo as discipline because of their damage output. The question now is: Can priests do harder content in Visions that require big pulls and interrupts?! Will time see people with priests then switching out to their warlocks and mages or even unsubbing altogether?!
Edit: If anyone is curious, I was playing five toons on a daily basis before 8.3–four of them healers. I am now down to one toon–and you guessed it, a healer. The daily visions, plus daily quests, plus assaults, you name it… Man. I have chosen my priest because Disc can do pretty good damage, most pertinently, doing Horrific Visions. This game has become so grind heavy and alt unfriendly, it is maddening–hence, this solution. As for healers and tanks doing Horrific Visions, Blizzard has made some positive changes since 8.3 kicked off, easing up the trouble a lot healers and tanks were having, and even making the content more enjoyable.