It's the transparency issue. If they came out and said this is a commercial venture people would think it either good or bad value. It's the hiding behind a charity that irks people I think. IMO 30 euro for a 10k in Dublin with closed roads etc is not the biggest rip off I have heard of in fact it's not bad value compared to some. I don't like this hood winking on the back of a charity tho.
Edit: Just noticed that the 30 euro fee wasn't an issue for you.