That sounds like a fine summation A2QFI. It is probable that the staff are deeply aggrieved about a number of aspects of their employment and have chosen this topic on which to strike. If I am correct in that first supposition, then my second would be that they have chosen it as they perceive it will be heard with more sympathy by the travelling public. If they chose to strike because, say, they were not as well paid as others in the industry (such as cabin crew of one airline compared to another) then there would be less sympathy.
Either way, my last guess is that the travelling public consider strike action to be a fossil best left in the last century. The reasons for strike action not working have been enumerated a thousand times.