They don't like how the other band is cancelling shows on their fans so they decide to cancel future shows for their fans? I get it isn't the same but still.
edit: glad to see I'm not the only one who thought this
The irony is pretty silly :-D
But at the same time, it still kinda makes sense to me. My guess it that TBTB is the headliner, and if they're actually that terrible to their fans, it could easily be a justifiable business move on the other band's part to leave the tour. Most of us will agree that bands airing out their dirty laundry in public only makes everyone look bad, but their actual (devoted?) fanbase would probably disagree.
I know if an artist I respected did this, I'd give them the benefit of the doubt and believe their assessment.