Yes, Axl Rose can be a dick and yes, GNR showed up a full 2 hours late to the gig (What, did you really expect they'd be prompt?) but thowing shit at a performer is stupid. Why did you even come and (probably) pay if you feel that much contempt for them?
It's like going to a movie with the sole purpose of ruining the ending for everybody (I think Batman is totes gonna die, btw.).
Or an athiest paying for a Vatican tour just to heckle the pope.
But less funny.