I'm weirded out by the random praise I've seen for Legion Brewmaster here and elsewhere, as someone who mained the spec for the last two expansions. We went from having 7-8 useful abilities and mechanics to keep track of in MoP/WoD, to having 2 useful abilities to keep track of in Legion... that share the same 16s cooldown... and one of them (purify) is just an old ability nerfed to be half as effective...
I logged into my Brewmaster to run some Mythic dungeons and couldn't believe how much they stripped away from the spec. I couldn't even fill a single bar with useful abilities, and what was left was just shadows of formerly fun abilities. Sure, Guard and Expel Harm had gotten too strong in those last few tiers of WoD and removed a lot of the thrill from tanking and healing, but the strength of and mix of abilities in MoP and early WoD was perfect.
Outside of watching Stagger and deciding to use Purify or Ironskin Brew, none of the abilities you press in Legion feel like they matter at all, and only serve to keep you busy and do mediocre DPS.
This is the spec design people are praising? Am I playing a different game than everyone else or something?
I've also mained Brewmaster since the start of MoP and had a lot of similar initial frustration. I think turning Elusive Brew into something totally passive, making Purifying Brew 50% and removing Guard while giving Guard with no cooldown to Prot Warriors were really frustrating, but losing Expel Harm was my biggest frustration. When they added that back during alpha to help with awkward movement situations I calmed down a bit, but honestly I still feel like a drunk, dodgy tank with high mobility, so I feel like the spec is still fun.
It takes a lot to get used to having less self sufficiency as a tank now, but I understand that design direction. At least our spec wasn't totally shit on like Blood.
I think Blackout Combo is something you've overlooked. You can use it to do more ST DPS, AoE DPS, pause your Stagger damage for 3 seconds, pull in a charge of your brews, it's up to you how you use it and it does have a noticeable effect if you do it consistently.
It's very neat in concept, but it's not quite good enough. Might be better served as a base part of the kit so that it doesn't get glossed over
Well, honestly, you just described the changes to every class. All of them are stripped down in terms of abilities. Brewmaster is now much easier to play for the average person, which is why you're seeing more praise for it. With that said, I think there's still a higher skill cap there than with some of the other tanks.
I will say this, Brewmaster was actually made either equally or even less intuitive and that's a design failure. If you only use one of the AM abilities (Ironskin Brew) without the other (Purifying Brew) you literally reduce damage taken by 0. It's not actually harder than other tanks, but not at all apparent to newer players