I agree with you for the most part, but the content that actually is there to try to pad out the time you can spend on the game is just so poorly designed that it's still frustrating.
Reps other than CoE/Frostwolves are already a ridiculous grind for their majority playerbase. I'm glad they don't give anything of real value so I don't have to bother with that bullshit, but still... why even put content like that in the game at this point? 5000 (Arakkoa) to 8500 kills (Trade Post) is fucking absurd. I can't even force myself to max out a single follower on one of my characters without using some exploit spot, let alone doing something as batshit insane as maxing them all on all characters. The same goes for apexis crystals. The armor you buy with them are so ridiculously overpriced that there's simply no point in bothering, and making the followers, mounts etc. cost 5k/50k gold on top of the apexis cost is straight up retarded. I do a couple dailies a week at most and spend them on my seals.
As for garrisons, the problem there (other than the barn and bunker) is still mission design. You go from mission overload which requires micromanagement every 30-90 minutes to having no missions worth doing at all. While I'm usually a fan of seeing micromanagement go away as there's nothing I hate more in gaming, the problem is that you get cut off from salvage boxes, and it's extremely hard to level new level 90 followers gained at the inn. Integrating garrison management in the b.net app would alleviate a lot of the problem, but it's not something I expect to see implemented anytime soon, if ever. And even that wouldn't fix the broken mission-selection algorithm they current use.