Don't let it get to you too much. Dylan fandom is one of the most toxic fan communities out there. Mainly because of the length of his career and age range of his fans. Used to be married to one, a large number of them really think they're the only ones who can truly appreciate his music.
Seriously, there's even a book about it. The Dylanologists: Adventures in the Land of Bob
I really like "The Dylanologists". https://www.amazon.com/Dylanologists-Adventures-Land-Bob/dp/1451626924
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I have not read the one you posted, but now it is on my list!