If you're using any term that means
penis as an insult, it's likely that you want a
strong,
vulgar effect. This is probably why the term "
wiener" isn't used much as an insult. It also has an air of
elementary school when things were
pee-pees and
private parts. However, for use on your
friends when they're being
dumb, the
term wiener should indeed be used more often. It would add to the
insult to make it silly-sounding.
But more important than the term wiener being underused, the item itself is almost always underused. Sure there are those few guys out there that are the exception, but in general, I say use them more.