One only needs to look at the Spirit MEC's resolution and how THEY defined what struck work would be. They spelled it out and decided what would constitute struck work in their eyes.

If you go back and read it, the resolution or statement or whatever you call it ALLOWS other carriers to come in with extra sections and earn revenue for THAT carrier's company as long as Spirit receives no revenue or financial gain from the operation being conducted. The new airline steals the passengers and the money right from Spirit's coffers.