I look at it like Pro-Bills and Pro-Winning.
Pro-Bills folks put their emphasis on loving the Bills in their current incarnation at all times, virtually no matter what. Pro-Winning put their emphasis on the Bills winning even if it would mean major change to the current incarnation.
Do the Pro-Bills group want to see them win, of course, but they put more emphasis on their love for the team. Do the Pro-Winning people love the Bills, of course, but they put more emphasis on seeing them become a winner.