Well, Android never went through an evolution like ipod+itunes > iphone +/- itunes, so the tools for managing it from another machine never needed to attempt to be friendly.
EDIT I would add that at least with adb its not the only option. Android is a reasonably open and flexible and open experience and there are lots of different ways you can manage your device. The iPhone for better or worse is locked down, the least Apple could do is provide something better than the lousy piece of crap that is iTunes.