If you invite someone as a special guest to a party, you don't just ignore them, do you! That would be very bad manners imo.
Absolutely agree. To be honest, the whole "OMG Bob is a legend, if I smile at him and he decides to ignore me that's fine because well he is Bob" thing is starting to annoy me. And for me, all the explanations are lame excuses, sorry. Legend or not, he is a human being and should be aware of the term politeness. Full stop.
Dylan has been living with other people's (often unrealistic) expectations of him since the early '60's- every utterance of his was subjected to intense scrutiny, the protest movement expected his songs to change the world- not just the musical world as they did, but actually change society. At the same time, Dylan faced harsh criticism, often from these same fans when he changed artistic direction-"going electric" at the Newport folk festival in '65 provoked howls of outrage from the folkies who complained he was too loud and they couldn't make out the words (sound familiar?); producing a softer country sound in the late 60's upset those who liked the "classic electric" sound; and as for the gospel tours, that put him beyond the pale for some.
So on the one hand, unrealistically high expectations, on the other criticism if you change- is it any wonder the guy has put up barriers, for his own self preservation if nothing else? And maybe if you've been living behind barriers for so long, it can be difficult to come out from behind them. None of us has had to live with the sort of scrutiny that Dylan lives under. If the people who are on tour with him are happy to cut him some slack so am I.