I think the problem is fans are more attached to the Smiths than Morrissey is and they are angry when he doesn't share their views. What people fail to take into account is that these are real people with real connections to each other.
Think about how you feel about friends you had twenty years ago (if you are old enough) and then you'll get some idea of how Morrissey just cannot have the sort of nostalgia for the Smiths than his fans can. Then think about how you feel about friends who let you down a long time ago (this is how Morrissey perceives it) and you are even closer to how he must feel. Then think about how you'd feel if every other day people kept asking you about this friend you had twenty years ago and why you didn't call them. Then think about how you'd feel if these people kept asking you why you like your current friends more than your half forgotten disloyal friend.
And there is a reason why Morrissey likes his current band more than the Smiths. They are obviously much more into live shows than the Smiths were. They obviously enjoy it more and therefore Morrissey probably feels more supported and it's more fun for him.