Jolie and Pitt give $2 million gifts

Who cares why they do it, as long as the money is put to good use and DOES help the people it should.

Angelina doesn't strike me as the type of person who would care what others thought of her (remember the whole vial of blood thing?), so she might actually be doing this out of good intentions but on her scale of income.
Other donators also issue press releases to that effect but those aren't widely reported in the media because they're not "celeb".

Look at Paris Hilton. Does she do anything good? Nope, and she'd definitely someone who would do anything to keep her name in the papers.