Is it allowed to win a game of cribbage with the single point from a "go"?
Indeed, I've heard much the same.
Turns out, it is merely a "common" house-rule.
There's no mention of any such limitation in any of the rules I've been able to find, but some people definitely play that way.  

It seems to me that in Crib (even more so than in many other games) it's important to know what the house rules are before you start.