I don't think he was rude per se and I think he knew exactly what he was saying. When you actually listened to what those questions were they were totally ridiculous. 'Does your music have a subtle or obvious message' WTF??
The bloke was just writing songs about what he felt and was being asked totally pointless, and impossible to answer, questions. When he was just saying 'What do you think?' to that one reporter he was just turning the tables on the reporter to let him see how ridiculous his questions were. When it turned out that the reporter hadn't even heard him sing he was justifiably angry. And that Irish couple who were so rude to him yet still demanded autographs, I thought he was quite restrained with them. Maybe he was the first example of how we think we own people who perform in public. I couldn't understand people paying to go to his concerts just to boo
eta - I did think that Joan Baez had more to say than she actually said