Not seeing the big deal here.
Pop is short for popular.
Van Halen is pop.
AC/DC is pop.
Led Zeppelin was pop.
What's the problem?
And Britney Spears is POP too. So according to that she should be in the same conversation with Zep, AC/DC and Van Halen, LOL?
In the sense that they are all popular artists, yes.
Or maybe you should read the whole thread and my later point...