I wouldn't personally go that far; having recently replayed all three back-to-back, I'd say that they're just very different types of games.
ME1 is a an excellent story-driven action RPG with clunky combat and issues with environment size/complexity due to technological limitations of the platform it was built for.
ME2 is a very good story-driven third-person shooter with excellent combat and a thin veneer of RPG elements that has overcome a lot of the technical issues with ME1 despite the same platform/engine.
ME1 by far has the better story and I enjoyed it more than ME2 on my first playthrough years ago, but now, already knowing the story, ME2 was more fun to play this time. It's a shame they couldn't have improved on everything good about the first one instead of turning it into a shooter.
Personally, I'd love to see the whole trilogy reimagined and remade as a single giant open-world action RPG, but that's probably never happening.
To this day, I would love to have a trilogy of games that were like the first one. Alas that Bioware basically immediately abandoned the direction of the first game for a much worse one in a misguided attempt to try to appeal to the mass market.
You're right. The sense of wonder and exploration I got playing ME1 was just totally absent in ME2. But it was nonetheless a pretty good game in its own right, and for many people, a game they enjoyed more than the original.
I loved ME1 and was disappointed by ME2 because I loved ME1 so much. I devoured the lore, every codex entry, and even the long elevator rides where you had to listen to news reports about your earlier actions. The world-building was so much better, and all of this was reduced to a minimum in ME2.
ME1 was an epic space RPG with action elements, while ME2 was an action game built around a collection of crew side stories with lighter RPG elements.
