No, you're right, he didn't used to be in so many crappy movies.
He was in Raising Arizona where he plays an imbecile (not much of a stretch if you ask me) and Leaving Las Vegas where he plays a drunk (with very few audible lines I might add), and did a good job in both movies.
While those were two outstanding movies, I don't buy that either one was credible solely because of Cages' acting skills, or even largely due to them.
Furthermore, since those two movies, Cage has flourished by taking legit acting roles in potentially good films...and proceeded to destroy them one after another.
IMO.
...but for those that love being treated to what is essentially Con Air 2, Con Air 3, Con Air 4, etc. More power to 'em. Let's just hope he doesn't botch World Trade Center.