Um, why shouldn't core gamers buy a wii? I like the games on it, so I bought one.
I've had a great time with Mario Galaxy and Godfather, and have played hours of Mario Strikers Charged and Brawl with friends.
RE:UC is great to play with my brother when we want to hunt down some zombies and Battalion Wars was fun when I just wanted to blow stuff up.
Heck, I've still got Zack & Wiki in its wrapping and have unfortunately not bought No More Heroes or Fire Emblem yet, despite wanting to play them desparately. As a core gamer, the wii has games that I like to play and will, why not get it?
Core gamer doesn't equate to "zomg I love FPS and pretty graphics!" Everyone has their own preferences