I can’t fathom why you can’t fathom why people didn’t like. But sure, I’ll bite.
It didn’t have a story. It’s unoriginal, basically the plots of ESB and RotJ thrown into a blender with the point of everything removed and little to no connection between any of the various plots.
The name Star Wars is synonymous with action adventure and TLJ didn’t have any satisfying action scenes. Rey is relegated to a support role, she does more meaningful action in the trailer to RoS than she does in all of TLJ.
Luke Skywalker represents hope and in TLJ hope dies because Disney didn’t want to pay Mark Hamill for more than one movie. Cameos should be enough for the fans, right? Think of the money the Disney coporation saved by killing hope!
There’s many more reasons it didn’t work for a lot of people but those are the big ones.