I fear the spillover of rouge onto the rest of AC.

When IROPS happen, and aircraft get shuffled around due to the ensuing schedule chaos, I foresee inferior Rouge aircraft being used on mainline routes. (for example, a rouge 319 on a Cuba run gets cancelled due to weather in the Caribbean. A mainline 319 doing YYZ-YVR goes mechanical in YYZ. The rouge 319 could do the YYZ-YVR. It could take days to get the two aircraft switched back.

On top of that, the inferior product being offered by rouge makes AC look bad.