Lack of imagination?
A clone of XpAntiVirus has recently been released, named as WinAntiVirus PRO. Those who have been around may remember WinAntiVirus PRO 2006 & 2007.
There are tons of rogue applications out there right now, most use unique names. It was just a matter of time before there started to be name collisions either on purpose or by mistake.
Finally a message to all fake anti-spyware/virus producers:
Do some research before you release new products; you might end up in court with your competitors because of name theft.