I'm sure that's the case in some instances. And people are definitely entitled to their own tastes, and how 'the latest' from a band they once loved, just sucks. However, I do get the feeling that a lot of this also has to do with fans placing their expectations on artists to continue doing what they always did, ad infinitum.
Personally, I think artists should be at liberty to explore whatever new ventures they wish, and jump as many sharks as their little waterskis will allow.
These two happily reside together in my iTunes collection: