Well the other admin on my wiki thinks red links are bad, meaning we should leave every use page, even if it is uncustomized. If I could be bothered persuading them, I would just say that we could say in the welcome link "Click on your red username at the top to make your user page!".
What I say whenever situations arise like this is: "If Wikipedia dose it, it obviously works." Sad thing is, Wikia and half it's community don't seem to agree.