Why are FANS the reason you hate the STAR?

Just saw posts on hatred for SRK, then some people calling Deepika names. Have no issues with that. They are my favourites but if you don't like them its totally your take. But I don't understand why are fans the reason you people have to hate the star. I have seen many Deepika fans behaving in the most terrible manner and calling Katrina names. But that's not a reason to hate Deepika. I have seen people opening accounts which say "RT for monkey fav for deepika". And reason? Because some X,Y, Z said something about another x,y,z and then they had a fight so you hate a certain star for his/her fans. Love a star for what HE has done. Hate someone for something HE did. What a group of people does is not the star's responsibility.
I actually hate the way SRK fans behave on Twitter. But that wont make me hate SRK. Salman , Aamir fans aren't any better. And the SRK fans are just sick people. But SRK has nothing to do with that. Any actor has done enough (even Sonam kapoor have reasons for which ppl can love her/hate her) for u to form an opinion why onvolve group of people who are not worth it. How can they influence ur opinion for god sake