The fanbase is the sum total of all a persons fans good, bad, and otherwise.
While the positive portions of the fanbase often outweigh the negative it can become irritating for yourself and others when your own fans are constantly harassing another persons fans or each other for essentially no reason.
Fans provide the vital service of spreading your name around for others to hear and come to enjoy your stuff much in the same way religious fans never shut up about how you should join there church and talk about there imaginary friend in the sky.
On the other side of this idea however you have the fans who spread your work like the crusades, by destroying, demeaning, or getting butthurt over everything/one remotely similar to your own work.
Pewdiepie Fanbase: Ubernovahaxor copies everything pewdiepie does
Ubernovahaxor Fanbase: Pewdiepie copies everything ubernovahaxor does.
The Nerd VS Critic years
The nostalgia critic fanbase: The nerd is a copycat of the Critic cause the critic started first
The Angry videogame nerd fanbase: The critic is a copycat of the nerd cause the nerd stated first
The critic and the nerd: ???