I wouldn't say subjective, the feedback is pretty consistent but dependent on how new and what content players are doing. Broadly it seems that new players who haven't gotten to deep, or players who do certain gameplay types genuinely won't experience what causes alot of complaints. More advanced players doing specific content are the ones who start to notice the cracks. Make of that what you will.
The feedback isn't consistent at all, everyone and his uncle has a list of demands from sensible to unrealistic. For every open only proponent you've got a PVE only proponent and even someone like me who says "pick whichever mode you feel like and don't sweat other people choices".
Familiarity breeds contempt. If you you play a game a lot you notice more, that doesn't make the game bad it increases your experience of it and the chances you've got a bit bored through grind if that's your thing.
What underlies alot of it though is an unspoken human assumption that generally, people doing something will try to do the best they can in the given context. I think people just assume that trying to do a good job is a valid thing to assert. Its possibility naive, but at the same time its better to have that attitude than not try at all. Which is subjective sureIts more about people unwittingly projecting that belief than demanding changes for themselves.
I think the fact you assume they haven't marks you as being unrealistic, you don't know their internal policies limits of the engine or current hardware any more than I do.
If they were not working on improving the game there'd be no expansions patches or DLC.
Edit :
Talking of unrealistic.
That would only work if they played the game that they're building