No you're wrong, and it's not that simple. Not all the people that have been "bad mouthing" Branch are going to run right out buying his jersey again if he comes back.
You're confusing a normal sunday fan with a fanatic... the fanatic quotient on a message board like this generally outweighs the casual fan, and many of the die-hard fans here are exactly the type that would never buy nor wear a Branch jersey again. That doesn't mean that IF he comes back, they won't root for him to catch that ball that Tommy just threw to him, that doesn't mean they won't wish the best for him while he's on the field in a Flying Elvis, that doesn't mean they think the team is better without him. However many of them are sincere in their feelings that since Branch has now shown that he is not (in their opinion) the "Patriots-type" player we all thought he was, they will no longer chose to single him out with their support and honor his name on their back. Book it... if he comes back or not, many here will never look at Deion Branch the same way again.
By the way, I say 'they' instead of 'we' because I'm just not a jersey guy. I got my #54 and that's all I want. Although I too will be seriously pissed at Branch, not that it matters to him, if he's not back by the first game. I root for the team, not the player, and if he's ON the team, I'll be rooting for him, whether I personally like him or not.