Oh you're right I forgot about the ShB revamp to GLA (I leveled it back in ARR, when it was undeniably the most boring job to level). Never let it be said that I don't admit when I'm wrong. I defer to LNC/ARC then as being the most boring.
Snipped for content, but all I see from your examples is that it actually was good and received very well, but was mismanaged by the developer. Hardly a reason to call it a rocky history IMO.
So I went and looked and while technically you are correct that there was a patch every 4 weeks or so, I didn't think you were actually considering timegating content as new content. That's my fault for assuming. I don't consider them deliberately holding content back and trickling it out as "new content every 3 weeks". With all due respect, neither should you.
I don't buy that TBH. While there are definitely carry's and carried; there's also an entire middle subset you're excluding of people who simply pull their weight. I have decades of albeit anecdotal experience in many games that just don't show this. You're always going to have all stars and bads, that's the nature of the normal distribution, but I don't think it's fair to simply pretend the entire middle section doesn't exist.
It all just comes down to bads. They exist in all roles. I've had situations where I, a full BiS geared tank with 2 near BiS geared DPS had a healer blame me for mass pulling and dying. He was like, we're not geared enough to do that (despite him being in what looked like full tomestone gear). I looked at ACT and he cast a single heal in the 16 seconds it took for me to die... He did not use a single oGCD heal either. When I called him out on that he proceeded to tell me that I was wrong and he was spam casting heals on me. Yeah good joke
Or if you guys remember the infamous shield lob only Paladin. Man that was a treat that paid dividends.
All in though, I do agree with you. It happens to me all the time (bads, in some way shape or form). Tank one obviously way less because I'm normally the tank.