I understand that you can sometimes get tired of signing autographs if you've been doing it every day for 48 years. And of course Ringo isn't public property and he isn't some circus monkey who's obliged to do whatever any stranger wants him to do.
But than again, I think it's really really lame if he just doesn't sign autographs period. Wouldn't it be amazing if you could make people really happy by doing something as simple as just signing your name on a piece of paper? And besides that, celebrities shouldn't forget that their fans pay their bills.