Your reaction is a bit absolutist. The basic premise is that if you're capable of making 500k a year in the developed world then going to Africa to volunteer to build houses is not as effective as just donating your money to charities that send people to help, or hire people yourself.

What it evolved into is a bit controversial, overall they seem to be a bunch of kids who don't know what to do with the power and money they had at one point, as they all came too easy.