I don't really mourn people I don't know. Sometimes I'll miss their work if I enjoyed it, but that's about it. I don't understand why other people do seem to take it so personal sometimes.
That said, there's no real reason to jump up and down on their grave acting like a jerk just to get attention either. If other people wanna express something over someone dying, and I don't feel the same thing, there's always the option of just staying out and letting people do their thing. Not like it's hurting anyone.