Tanaan Jungle is STILL completely inaccessible. Farahlon's been removed, so was the other island on the south side of Draenor. Ashran's a broken pile of garbage since the start; It's Warsong Gulch with a road in the middle, it was supposed to have been the new Wintergrasp, then it was demoted to being the new Alterac Valley. Right now it's just "That thing everyone hates but still has to do it", I haven't seen any positive feedback about it at all. PVP has been insanely poorly balanced from the start, still hasn't really been fixed.
Dailies, took too much time to make those, so now grind until you fill up a blue bar. Hey wait, isn't that how you level in Korean MMOs? SHH. Pets were supposed to be able to breed and make new pets. Garrisons had more plots, and more buildings to choose from, Karabor and Bladespire were removed as cities because god knows that would've cost us a raid tier.
Some classes are badly, badly in need of a revamp. Shamans, anyone? But that shit's not coming, that would require effort, instead we'll just leave shaman in the worst state they've ever been in, and that's saying something. Their numbers are a bit better now, but it was absolutely inexcusable for them to have gone to launch how they were. Oh, but the world's best shamans were all "playing wrong", according to blueposts.
Orgrim's storyline was chopped, all mounts are just the same 5 or 6 mounts, some of which already existed in the game previously, oh and none of them have running animations, just walking animations sped up to Plaid. Even LESS dungeons than MoP had, and now without scenarios. Weee! A massive amount of class variety was removed because of "bloat", when in actuality it's just easier to balance. Survival hunters? 0 cooldowns to use. Boy that's sure fun. Healers have to choose between slow medium heal, slower big heal, or quick inefficient medium-big heal? Eh fuck that shit remove all options, also remove all instant casts because it's easier to tune difficulty/maintain balance if all of them can't move instead of some.
Blood elfs have no excuse to have not been in 6.0 other than stringing people along when 6.1 came out. Belfs are the most popular race in the game, a long while back they put out a poll for "Which race do you want to see updated next?", and it was overwhelmingly voted for blood elf. Even before human males were shown, blood elf won that poll by a landslide.
The other races were updated in 6.0, which was the expac drop, just that WoD content was locked until the expac's release date. There's no excuse for a company to spend the longest development time on a product, only to go "haha, oops. Well, we'll patch it in later.". And then later comes, we get new models and twitter.
Woopity-shit. What even took 6.1 that long? Cause it damn sure didn't have a lot of content to be developed, that's for sure. They didn't fix any of the core issues with the expac, apexis are useless, dailies don't exist, reputation is an absolute bore and useless, garrisons are a shittier version of the farm from MoP, except lacking in the charm that MoP's farm had. Some classes are pretty fucked, when's the last time you saw a Gladiator warrior? Oops, we'll get that later.
That's what has a lot of people pissed off, the first major content patch for an expac with a TON of holes, fills absolutely nothing. That's like having potholes all up and down your street, then the city says "We'll fix it in 2 months!", then they come and put a sign at the end of the street that says "Caution, slow down for potholes"