Originally Posted by
Thage
Monks have a few things going against them, and I say this as someone who's loved the class since its debut in MoP.
First up, Windwalker has a big problem with being chronically undertuned. Just about anything a Windwalker brings to the table, a Rogue will bring to the table and do better at it. Windwalker also feels less intuitive to play than it did at release--in 5.0, WW's rotation flowed smoothly, whereas, like with many classes throughout BFA, the rotation flowed as well as an engine in dire need of an oil change.
Second, Brewmaster has more or less been the redheaded stepchild of tanks, sharing the gig with bear druids. Stagger and Guard worked splendidly for PvE out the gate, but it was a problem in PvP, and Brewmaster has been on a pretty consistent revolving door between playing well and, again, bringing very little to the table another tank spec doesn't do better. Luckily, they seem like they're in a good place in Shadowlands, from what I've seen thus far.
Third, Mistweaver, like the other two specs, has suffered from "Who am I?" syndrome from WoD onwards. Blizzard had a very clear vision for the class and its three specs in MoP, but from WoD onward that vision has become blurry and muddled. One of the worst things they did to Mistweaver's identity was get rid of Fistweaving and stop supporting it as a playstyle beyond some minor concessions that clearly aren't meant to make it a supported playstyle, like how Dark Apotheosis didn't make melee Demonology Tank a supported playstyle. Its other problems, again, are shared by its sister specs. There's not a whole lot Mistweaver brings to the table that other healers don't.
Fourth, monks start at level 1. While this might not be a huge issue, being the only class added after launch that isn't a hero class means by definition fewer people were going to give it a go. This problem will probably all but evaporate with prepatch's level squish, so I'd keep an eye out for potential upticks in monk representation going forward, though how big and long-lasting relies entirely on how well monks do with SL's updates.