Windwalker is not good at the moment. It’s not the worst either, but it needs some more love that other specs are currently getting. Let me elaborate.
In 3s and shuffle, windwalker is currently hard countered by frost mage, devoker, and all hunter specs. If anyone queues 3s or shuffle, theres a 90% chance each game has at least one of these classes, on all elos.
In blitz, which is fotm mode and growing in popularity, windwalker is only good on flag maps chasing enemy flag carrier and okay on base maps. Windwalker is terrible on teamfight maps like gilneas and silvershard, as its teamfight damage is very lacking compared to some other specs (uhdk, affli, mm, destro etc.)
Currently windwalker is just a low budget hunter. The only good thing about ww is its defensive toolkit. A ww has less damage than an mm with full uptime, and is a melee. In a realistic arena scenario you never have full uptime as melee, which means you are doing ALOT less damage than a hunter.
ww also has worse cc and debatably even worse defensives (hunter has 90% dam reduction feign death every 30 sec, double wall, big heal, turtle, pet sac, freedom)(essentially matching and having 2-3 extras ontop of ww). Hunter also has a root to guarantee its freezing trap, which also lasts longer than the monk incap, while also having a second backup incap. Ontop of that hunters have a blanket silence, a ranged interrupt and a ranged stun. To add the cherry ontop of the cake, hunter also has mortal strike (as does ww), effectively making windwalker just a bad hunter.
Why would any good dk wanna play with a ww instead of a bm atm? literally no reason, god tier comp vs b tier comp. Why would any feral wanna play with ww? also no reason. Same goes for sub rogue. Would any mage pref to play with a ww? nop. Essentially all the comps that ww has been good in the past with, have better alternatives to play with.
Solution: Increase ww damage slightly, probs 3% overall. In addition to that, they need some love on the cc. Make the incap be atleast as good as the hunter one is and increase its range. Windwalkers also need an additional cc to be in line with hunters as a toolkit. Right now it seems like, unless ww damage gets buffed by alot, it will still just forever be an underdog to hunter.
Edit: WWs biggest strength is countering melee comps with FOF parry and decent cleave damage. In the current meta, there is none of that happening. The incoming nerfs to fury/arms etc are just gonna reduce the classes ww has a change to prove itself against. As a result more hunters, mages, evokers in the ladder which just makes it almost impossible to play. I think ww needs abit more to its toolkit to be able to play against some ranged classes. Maybe a 2 stack diffuse? idk.