Review bombing is usually used to make a statement. When the game is crap for one reason or another it just get poor review. For example, Odyssey.
I wouldn't call it review bombing but you are making it too easy if you just say reviews are poor because Odyssey is crap.
Lots of people give it a bad review for nonsensical reasons like no VR support, no ship interiors, FPS instead of full atmospheric planets, etc. Nothing of that was ever announced to be part of Odyssey, so these people aren't reviewing the game, they are just complaining that they don't get what they want. That reminds me of my 4 years old daughter by the way.
Lots of other people are giving it a bad review because they don't like or are disappointed of the company rather than the game. They are reviewing the poor launch, console support, broken promises, etc. They can hate Frontier as much as they want, it's completely unrelated to the quality of the game.
Many people gave it a bad review for the bad performance and issues at launch / the first few months, without changing it after many problems were fixed.
Of course something similar can be said about positive reviews, many people give it a positive review because they just love the game despite the issues and bugs. Somehow that's not completely unjustified though.
That doesn't mean all negative reviews are irrelevant, but I do have the feeling that Odyssey gets more "undeserved" negative reviews than most other games, simply because the Elite community is
very emotional about their game.
PS
Personally I still have mixed feelings about the expansion. Performance and issues are still a problem, so many missed opportunities, bad exploration gameplay, connection between base game and Odyssey is basically not existant (it's like an entirely seperat game within a game), planet tech is not always an improvement - on the other hand it's pretty awesome and unique. No other game manages to do what Elite Odyssey does.