When a company ‘gives back’ to the world through charitable donations, should we wholeheartedly commend it for being a good egg or sniff cynically at the profit potential that underlies every business decision?

You have the same problem with people. If someone helps someone, knowing they will be praised for it, what is there motivation? We generally accept that being good and looking good can BOTH be a motivation for the same thing. For a small company, that can clearly be the same: a few shareholders, a few officers, they all do that. For a big company it's a lot harder to see, and more tendency to attribute goals to the company as an iindependent entity, which it isn't really.