I don't understand why they are so adamant about ads... A small adsense block (with 2 text ads) will cover all their expenses and more. It will not be intrusive

I don't understand why they are so adamant about ads... A small adsense block (with 2 text ads) will cover all their expenses and more. It will not be intrusive and useful to visitors in most situations (as their content is well suited for a contextual ad system like adsense)...Also there is precedence in non-profits doing this like firefox with their google search deal (which makes them $100 million or so a year)