It's kinda interesting to look at the reaction because Star Trek has a pretty tightly moderated continuity compared to most things. Several series all in the same universe, references back, a whole EU devoted to continuity... so for the fans who're into that, something that is potentially at odds with that continuity probably would bug them.
It's just weird to me because, well, Doctor Who nerd, and the DW EU is utterly bonkers and leaves the Doctor with three possible parents over the course of one book and people forget alien invasions happen every other week. You get fandoms like that were continuity might be a fun puzzle for uber-fans, but beyond that it's just common elements and references and familiarity telling a whole variety of stories, which I think's how most people engage with media. Then there are people who enjoy the sense of one continuous narrative and don't like losing that sense of immersion when, to use one complaint I saw, drones pop up in a two-second snippet of the finale when there was a whole TNG episode about how remote repair drones don't exist. Which, eh, I'm not going to tell people how they can and can't enjoy things, it's a valid reason to like something, easy to see the appeal of a centuries-spanning story. There are just people that can't tell the difference of 'not to their taste' and 'objectively terrible.'
Discovery's not perfect, but after the uneven S1, S2 was so good.
Also the shorts.