That is it exactly.
[Disclaimer: I'm a Sorc healer main. My team is not the best, not the worst: we continued to go for NiMs in 7.0, managing to kill most "pre-bosses", even got some end bosses - most of them are alive and well, though. The game still feels like the bones of itself.]
It's not that Operative is OP. For NiM, it is *not*. It's that the other two classes are not good enough.
That one skill heals 8 people, on each one just as much as the Sorc's biggest single (or double) big heal on one (or two) player(s).
And what gives salt to the wound: they even nerfed the *Sorc* Resurgence spread (which was a badly thought-out skill to begin with), as being too OP for an AoE. No comment. (Yeah, PVP balance. Riiiiiiiiiiiiiight...)
(I'm not good on Merc, so I'm leaving that part to the people who have finished playing Merc heals recently because they didn't enjoy it anymore.) Did they give it back at least in stronger single-target heals? *No.* The other two classes have almost nothing to compensate.
Playing one of the two "lesser" healing classes feels like watching a great Arsenal playing next to an average Fury Mara: hopeless.
(Another example of "great" scaling. The nerf BW is planning on most classes is just ridiculous.)
You can sacrifice a kidney and a lung, and you' still feel you're underperforming in comparision, getting carried by your team. And I say it as one who progged a few NiMs with two Sorc heals on team in the expansion when most people said the class wasn't even viable. Well, "not viable" for some last bosses never felt this close to being true.
And it's not only healer classes.
It's not even the question of "there are always meta classes". In 7.0, it's like there are 3-6 specs that were *made* to handle NiM level, and many which were just left in the game because taking them out would cause an uproar.
I can already hear top-level players laughing on the whole thing: "stop whining, get good and learn this and that classes. If you don't enjoy playing those, just search for a new game, or be satisfied with HM."
Since people are still doing sale runs in 7.0, which means they must be able to 7-man Ops, I have to admit: there must be truth in it.
On the other hand: if there are only a handful of classes/specs good enough for endgame, that is just bad design. If the game is scaled to be satisfying only to the best 20 players on every server, it's bad design.
Okay, technically, Mara and PT were OP for at least the last few expansions, boring as this status quo is, we all could have learnt them by now. (Don't mention the nerfs/buffs, I've heard players laughing out loud reading about those plans. I'll check the Parsely leaderboards with great curiousity in 7.1.)
The devs probably didn't have the time and resources to do proper scaling, but this expansion felt like torture, with 2/3 of the content (and raider playerbase) suddenly snatched away.
On kills I didn't even feel satisfaction, just "if we'd like to play this and that classes, we could have this on farm already."
I actually feel dumb for not planning on unsubbing because of all this ( I just love this game too much, even in this state), and in 7.1, wearing 340 will provide the missing few thousand heals/dps, so balancing it doesn't matter *that* much - then again, being able to do something, vs being able to do something with one hand while tabbing out every 10 seconds and chatting with people just because of using another class is pretty much unfair.
After the relatively balanced 6.0, the unfinished state this expansion stands out even more.