I think I was one of three people that enjoyed the Wing Commander movie, even though it had very little relation to the game canon.
I think that movie would be better received if it was released today instead of 19 years ago. We’ve had close to 20 years of comic book movies that are mostly divorced from their source to make such a source-material-disjointed movie more palatable.
Even the whole "broadside" missile launch like old war ships with cannons.
Despite the departures from the game information, I didn't hate it like so many others did.
That said, your point is fair. Most book to movies, I though, typically strip out a lot, but don't fundamentally change the story. Do they?
Of course, as this article points out, the story for this game wasn't nearly as good as my rosy glasses give it credit for.
Wing Commander felt different because it was basically keeping a few of the names, but a completely different story. Not even the same mechanics, since there was no magic to the main character in maneuvering through space in the games. That just came out of nowhere.
Like World War Z. The screenwriter perhaps looked at the title of the book for inspiration, but that much could be coincidental based on the movie.
The problem is that a movie's fundamentally different as a storytelling method. You can't give the same insight into a person's mind. You can't reveal things about a character or situation that are intrinsically visual by describing them later on. Film is visual, it needs to show, but it's also not engaging in the same way a game is.
You can give people a taste of surviving in the wilderness, on a far-flung planet, at the bottom of the ocean in a film, but these films are at best a few hours long.
A game can take forty or more hours to complete and you're that much more immersed in the world. To replicate that experience in a two hour movie is impossible.
Not to say that some of that time can't be immersive, but it isn't as extreme as the time would have you believe.
Oddly, the closest direct competitor to the two hour movie, is the multiseason show. And even those have trouble making the jump to larger formats.
I think the truth is just that story telling is hard. Crossing mediums of any kind is far from easy. (Though, I have grown rather fond of audiobooks.)