It’s actually pretty good as a film. What’s interesting about it is that the writers took the source material and said “and how do we make this into a movie?”
And it works.
The story depicted in the first movie wasn’t in any of the comics. There was never a story where Rogue was used by Magneto to turn world leaders into mutants. For much of Rogue’s history she’s had Ms. Marvel’s powers and became a badass. Jean Grey was “the weak woman unsure of her powers” in early comics (because it was the 60s) but I’ve gotten used to her as powerful.
Indeed, if anything there is no “origin” comic for the X-Men and it benefits from that. There’s no obligation to play out a story people already know. Which is why we’ve seen Peter Parker get bitten by a spider and let his uncle die multiple times now.
That’s how you can just use the material as a source to make a better movie. And that’s what they did with the first two films. They dropped just enough proper references for us nerds to get giddy, but then just made a movie.
It being the first film also meant that it didn’t have to deal with Hugh Jackman now being a huge star, nor Halle Berry. Wolverine was always excessively popular in the comics and that popularity translated itself into general popularity with the films and that helped to ruin them by giving him excessive importance in a story which didn’t necessarily need him.
What’s important is that you can watch “X-Men” as someone who isn’t a comic fan and still see it as a good film. The early scenes of the concentration camp, and Senator Kelly’s hearing demanding the registration of mutants, humanizes a film which centers around people with superpowers.
As much as I love the medium of comic superheroes, the reason it is difficult to film is because it’s sometimes easy to get lost in the spectacle of BOOM WOOSH WHAM SMASH and not in the emotional core of what makes any individual story worth telling. “X-Men” manages because it made its own story.