Actions which increase utility but do not maximise it aren't "pointless". If you have two charities to choose from, £100 to spend, and you get a constant 2 utilons/£ for charity A and 1 utilon/£ for charity B, you still get a utilon for each pound you donate to B, even if to get 200 utilons you should donate £100 to A. It's just the wrong word to apply to the action, even assuming that someone who says he's donated a small amount is also saying that he's donated a small proportion of his charitable budget (which it turns out wasn't true in this case).