those who want os4 won't buy a g5 mac.
Clearly not. But those who objectively compare MorphOS and OS4 might actually get MorphOS instead, especially when the hardware is so much more affordable.
on a g5 mac won't run win7
I'm not quite sure how that is related, but indeed PowerPC hasn't been able to run windows since Windows NT 3.51.
if i want a red "apple" why have i to buy a yellow one?
Yellow ones are better and 1/4 the price.
it's a matter of taste.
You have expensive taste.