why do people think pagans are bad?

My advice: If you want to be in a certain religion, make sure its for the right reasons. Cool, isn't exactly a good reason...

Paganism is a wishy-washy, pick and mix religion where individuals decide which parts sound exciting and discard anything else that doesn't fit their modern outlook. If they were prepared to actually follow genuine pagan beliefs, they might earn a bit of respect from me, but wicker men don't seem terribly popular nowadays, nor other forms of blood sacrifice. Like you say, it's 'cool'. And that's all it'll ever be; a trend angsty teenagers and arrested adults pick up to rebel from mainstream society.