Why is that?
I think white receivers like Wayne Cherbet and Steve Largent proved it's not all about speed!
Um, Wayne Chrebet never made a Pro Bowl and Steve Largent was drafted back when there were plenty of white WRs.
Since it seems to be impossible to continue this conversation without involving the race card, I'll just say this:
Wide receivers these days are expected to be tall.
Tall players that are black usually end up being groomed for WR.
Tall players that are white usually end up being groomed for...
another position. (Miami's most recent draft pick is an example of this.)
Just take a look at how many black QBs in college end up becoming WRs in the NFL. (It is far from uncommon.) So I wouldn't exactly say that the lack of white WRs is due to anti-white prejudice at the WR position as much as it is that a 6'3" white player is going to be slotted as a QB instead.