Dribble and handling isn't the same.
Have you ever seen Oneal dribbling ?
Centers makes only move -> Handling
I didn't meant to imply that dribbling and handling are the same thing, just that dribbling is a part of handling the ball and that every player on the court does it.
Yes I have seen O'neal dribble, every single game I have ever seen him play. Some players are more effective when they don't have to dribble much but I have yet to see anyone play the game for significant minutes and not have to dribble.
I'm not sure what your last point means, but I agree that inside moves that centers have to make involve handling. Spin moves, drop steps, backing an opponent down or facing up all inolve handling the ball. Being able to handle the ball well will lead to better shot opportunites.
The point I was trying to make was that while a center can be effective and very valuable with poor handling, handling does help but does not make up for weaker inside skills. If two big men have equal skills in everything except handling, the one with more handling will be better.