It's the pressure of having to look different from others, or maybe they just like to be noticed that our very great designers dress in a very outlandish manner.
Take a look at this...

Crikey, Zandra Rhodes resembles big bird from Sesame Street.

At a black tie do, Alexander McQueen certainly looks different...

It would all be OK for Ben De Lisi if it wasn't for the jacket.

Is that a painted-on tux Betsy Johnson?

Which is more than can be said for John Galliano.

Patrick Cox's leopard print coat is just awful