Buying the expansions + paying the subscription is already very expensive for a game. A game this expensive should be quite excellent in all conceivable aspects. The fact that they also have various paid services + cash shop cosmetics like a f2p game is a huge revenue boost for them.
And yet, I the quality of this game surely does not justify the subscription.
EVEN IF you enjoy the game in the appalling state it's been in for years, there are some universally unacceptable issues.
The lag, the disconnections, server crashes and restarts, the AH being incredibly slow, there's a default delay of 130+ ms on all outdoor zones etc... they've been going on for weeks. Blizzard blames the customers instead of trying to fix the problem, and anyone who loses anything because of the disconnects is shit out of luck.
Another glaring issue are the bugs. This latest patch still has a myriad of bugs week after release. How is this acceptable?
Combine all these with a major patch that has barely enough content to last a month, much less the many months that it will be till Shadowlands, I can honestly say there are F2P games out there who put out better content, more content, less buggy content, and with servers that actually allow you to play that content.