I'm sure the people it helps won't care whether it was a publicity stunt or not. People who stay stuff like that often say it so they don't have to feel as bad about not forking out themselves.
One justification given is often that it could be done anonymously. It's difficult to give out that sum of money anonymously, and if you do people will always ask why you did nothing. Also, one has to consider whenther he felt that, since he does have quite a few fans (or so I've heard, I really don't keep up with these things
), he could lead by example.
I don't think liking him or not has anything to do with it.