I agree with everything said - it's almost certainly a combination of lack of quality VAs, poor direction and lack of context given. I do not believe for a second that any of the English VAs are fans of GuJianQiTan and studied the characters, lore and culture extensively. This was just another typical MMO job for them. It's really detrimental to the game reputation and player experience.
It makes me sad. I cringed seeing big Youtube streamers/reviewers playing SOLO in English, and then seeing the absolute onslaught of mockery towards the VA in the comments.
It comes back to this for me: Voice Acting: Alert new players to their options (CN or EN)
I feel like a lot of problems would be solved if the options are laid out for the players right off the bat. At least this allows them to think; "Hmmm. I can play with the Chinese VA for an authentic experience, or I can try the English VA even though I know it has a bad reputation."
Offering the authentic alternative as visible option is the best that can be done at this point - since they sure as hell aren't going to re-do all the English voice acting lol
I went through this with Blade & Soul - except I had to download the Korean voice packs and use a script to swap all voice files into Korean every time I launched the game. I had a pretty good grasp of the language, so it was absolutely appalling to me to see how dumbed-down the translations were compared to the actual Korean dialogue.
Meanwhile my brother was playing the game in English, which made it like an ENTIRELY different game with drastically different character personalities. Insanity.
The only MMO I've played so far that actually has quality voice acting, with VAs that actually grasp the characters and story, is Guild Wars 2. However, that's a western game that is made IN the west - rather than quickly dubbing a ported Eastern game.