Well, before I start, I'm not (or rather for a long while no longer) a WoW fan, but I did briefly try it again recently. So, you know, I'm only having a superficial impression. I don't think I'll bother much with it, but...
I think that as far as "dumbing down" goes, it really sounds worse than it really is, when you do the Vulcan thing and think about it logically.
1. Most of the stuff you'll only notice if you've played it before and have any particular attachment (even if just for nostalgia sake) about the old system. Truth is, I most other recent games are just about as "dumbed down".
You can play TOR for example as a DPS Trooper with little more than Grav Round, Full Auto and High Impact Bolt as the only three buttons you'll ever have to press. Heck, you could play it with Grav Round only, if you don't mind losing a little DPS. Trust me, that's actually less skill needed than WoW even now. (And obviously the Bounty Hunter is the same deal, just with different names on the buttons you press.)
2. For that matter, it's not really dumber than WoW used to be to start with. Anyone remember the pre-Burning Crusade raids that some classes only needed one button to get through? Ironically, for all its reputation of a noob class, the Hunter was technically the most "complex" to play since it needed a whole THREE buttons. Yeah, you also needed to set the hunter mark and send the pet, so, yeah, that's a whole two whole extra buttons :p
(Not to mention you had more typing or talking to do than the raid leader, what with having to tell everyone that yes, the pet was on passive, every time anything went wrong, no matter who started it or what actually happened. You could be still running back from the cemetery when the rest of the group did something stupid, and they'd still insist that it's somehow the pet not being on passive that caused it. I mean, it wasn't even in the dungeon, but it must have caused it. Somehow.;))
Yeah, it didn't really start as a sort of modern day chess or go or other complex thinking game. Nor had the geekiest and smartest population. Really, it was from the start a game that 6 year olds can master.
So let's get on to what really changed:
3. So now for a bunch of quests you don't have to run back to the quest giver to get the next step of it. Well, it takes some getting used to it, but at the end of the day, it's not like running back and forth was actually the fun part.
4. You don't have to keep buying skill upgrades every 2 levels; they now increase in effect with your level. Not only it's like how a bunch of other games were working already (e.g., COH), but basically if you've been on the game long enough to have a valid whine about being used to the old system... guess what? Paying a few coppers to buy the skills on a new alt wasn't really a balance factor any more anyway.
Plus, again, running back to wherever your trainer was, and then back, was hardly something that added any fun.
5. The talent trees. Well, the issue with those is two-fold:
A) Most people were going for cookie-cutter builds from some site anyway. Not just in COH, but generally. Whether it's actually talent trees (e.g., TOR, RIFT, etc) or putting points in some skill (e.g., STO), most people just want something that works, not to solve a puzzle. If there had been some way to tell the computer "just go by this build off that site" automatically, most people would have just done it. And in effect that's what the new system does.
B) You haven't actually lost much. In addition to the choice every 15 levels now, many of which are actually new extras, a bunch of the old talents everyone took for a given spec are now automatic passive skills, that you get automatically when reaching a certain level. So, you know, you haven't actually lost them or anything, and they were not that much of a choice in the first place anyway. Now you just get them automatically instead of having to click through the tree.
C) Basically it doesn't let you make many mistakes. And believe me, a lot of people did make mistakes on their spec.
6. Stuff like that now hunters don't get a melee weapon too, or mages don't get a staff AND a wand. But if you think about it, those never really made a difference, except for causing all the drama about whether the hunter or the rogue should roll for those daggers.
Actually fighting with the staff auto-attacks was never viable past, say, the first 20 levels, as any of the magic classes, so that having both wand and staff didn't actually add any tactical choices or anything. It used to be just a meaningless extra accessory slot, and the new system just does the same thing with one less slot.
And for hunters it's not like it was much of a meaningful choice either.
Plus, again, it's not like the other choices of a game do it any differently. It's not like TOR lets you do any meaningful switching between rifle and melee weapons, for example. Even when you have vibro-knife as a second weapon (e.g., Imperial Agent), it's not like it's used for more than one situational attack that you do mechanically.
And so on.
Basically it seems to me like you haven't really lost anything in the process. If anything, the game is actually a bit more complex where it matters, namely dungeon tactics and the like, than when it started. The simplifications in the parts that at best offered an illusion of choice (e.g., the talents) don't even come close to offsetting that.
Plus in the meantime you actually do have more choices than when the game launched. Granted, it's not Pandaria-speciffic, but a lot of stuff that was previously at best a noob mistake to take, is in the meantime actually a viable choice.
E.g., have you actually tried to play a survival-spec hunter at launch? Yeah, it used to be the joke spec. Now it's a viable choice.