Well, if this were Voltaire's Candide and we were living in the best of all possible worlds, then all this ranting about other unions doing struck work and crossing picket lines would be productive. However, we are not and it is not.
The truth is that unionism died a long time ago. When I was growing up in Birmingham, AL in the 50's and the coal and iron ore mines and the steel mills were still operating, no one crossed a picket line, period. (Except maybe an ambulance.) The strike could be by the office janitors at the steel mill office, but that was good enough. A union brother was a union brother. End of discussion.
In this day and age, the great majority of people including union members have a "me first" mentality that says "I'm with you, but I have a mortgage to pay and a car payment to make, and I want to go on that Caribbean cruise next summer; so, I'm afraid I'm going to be forced to cross your picket line." Therefore, you are going to have to risk standing alone for principle and a better contract and working conditions. And, you can be pleasantly surprised if someone not in your union decides to support your strike by not crossing.
The behavior of passengers on the airplane is a microcosm of U.S. society today. "I'm going to put all of my carryons in the overhead because I was here first, and I don't want the space under my seat for anything but my bare feet. The cabin temperature needs to be adjusted to my personal comfort even though I came on the airplane half-naked. I have to be first getting off the airplane because I have a tight connection (translated into the English, I want to stop at Starbucks on the way to my next flight) ; so, you have to make a PA and tell everyone else to remain seated until I get off."