No offence mate, but I think you're the deluded one if you honestly think City fans would stop attending en masse if we joined a Super league. The majority would be signing up for season cards on the first day they became available. The price would no doubt put quite a few off, but that would be small potatoes in terms of losing revenue.
Bear in mind that it wouldn't necessarily be City fans attending. Every club linked to the Super league knows that football tourists / corporates / hospitality types would fill grounds at every game. It happens with the CL, so why would it be any different in a Super League?
City have been targeting the wealthier type of supporter for years, and we've seen a move away from trying to please traditional (low spending) fans. The Super League is the future - Don't kid yourself that City weren't interested, they'd be fools not to be. The advertising revenue alone would blow the PL out of the water. The richest clubs in Europe all want in. It will happen soon.