4. Short Treks - F
Objectively this was a show that failed to really grasp what Star Trek really was at its core. They made some good shorts, but for the most part, the shorts were either forgettable, unimportant or downright lambasted by the fandom. It's one of the only shows to get just a two-season order, and that's in part due to the fact that no one was really watching the show.
At the time the show came out, Paramount+ was throwing money at everything, so had it been gaining some kind of a fanbase, it likely would've had more than just two seasons. Especially with all the hair-brained ideas Alex Kurtzman had wanted to see Star Trek embrace.
Discovery (D-)
Star Trek: Discovery started off bad in season one, but somehow got worse in season two, before finding something interesting in season three. Season four was flat and season five was lambasted for telling a story no one cared about. It was a wildly inconsistent show that tried to cater to a specific set of fans as opposed to the entire fandom and it backfired routinely. It's often seen to be one of the worst-rated shows in the Star Trek lexicon, and its legacy is a show that bucked established Trek principals in the face.
It's third season saved it from being an utter train wreck.