This is a very unfair forum topic. How can you judge someone based purely on one incredibly brief meeting? We all have days when we'd tell even our most loved family or friends to sod off, so you can't expect celebrities to not feel the same.
Many of these stories lack any context. You don't know whether the chap who Tom Baker alledgedly told to f**k off was incredibly annoying and harassing him.
Let's not be so swift to judge people so quickly. Enjoy what they give us in the films and TV shows they appear in and stop expecting people to be a far better human being than you are 24/7
It is pefectly excusable for any celeb to refuse to sign autographs if they are pushed for time but they should do if pleasantly. To tell people to **** off is inexcusable unless they have been wound-up by whoever it is directed at. Recognition, which is sometimes not welcome, is the price of fame.