What makes an exercise a good exercise? Most people would agree that judging an exercise by how effective it is makes a good exercise. One of the most important criteria then in judging the effectiveness is how much muscle it stimulates. Again most people would agree that overall the deadlift is a better exercise than the bicep curl in this regard (as well as most others).
Let's examine the OH press by this standard.
Deadlifts, squats, bench press, chin, dips, barbell row, T-bar row, leg press. clean and jerk, and snatch are all good compound exercises and ALL work more muscle than a strict OH press. As we can see the OH press doesn't even make the top ten. As for arguments about "core" I would posit that if you can use more weight in these other exercises, that your core is worked harder. (It is assumed that good form is used throughout). Furthermore if you have a lot of indirect shoulder work you may not even need this exercise.
While the OH press may be a good exercise for intermediate and advanced lifters (I do some OH pressing myself) I believe that beginners should stick to other compound exercises that work more muscles.