I'm sorry folks, but which part of "One and only one" is not perfectly clear to you?
Aside from the other reasons mentioned, having two compressors gives a team an unfair advantage, since the on-board compressor is not being run as much. This keeps it cooler, allowing it to be more efficient and effective.
Seriously: Follow the rules or don't, but if you don't, stop trying to rationalize your cheating.
