“I’ve always wondered why God would design us with a desire for something which He knew would be ordained as improper.”
Anything good can be corrupted, except love of G-d and following his commandments. (And even that can be twisted.)
A healthy sexual attraction overdone becomes lust.
Love for another can become obsession.
Enjoying food can become gluttony.
Patriotism can become nationalist facism, etc.
OK, thanks for the answer.