Why do private servers have bugs?

[Dag001]

I don't mean to sound picky or come off like a brat. Why do private servers always have bugs? I remember back when I played retail UO, then switched to UO gateway. The two were the same. So how come WoW isn't like that?

[su3n01z3]

becuse they have to make (most of the time) all new servers everytime a ptach comes out.. and in-between the patches no one wants to take the time to clean out all the bugs when thier going to have to re-start when the next patch comes...