Asking for donations isn't a problem, even for a for-profit company. The problem is that they set expectations of how the money will be used, with no way to verify it. Saying that Ubuntu is a community project whilst funnelling the money generated directly by it  to a for-profit entity is certainly contradictory to me.
I hope they don't need that money to pay for my friends' salaries.
: The aforementioned donations, the Amazon referral system, the Magnatune referrals, etc.