It's still a competition to see who did the best logo. The person who wins will be the person who most people vote for and I think that's a pretty great achievement in itself. And their logo will be used by the majority of people anyway.
It's just that some people really aren't going to want to have the one that wins, which ever one it is... And it seems that this dropbar/logo-option works fine, so why not have it?
That way you're making everyone happy, and we're still having a valid competition. I can't see a downside.