I am under the impression that they did not strike due to fear of reprisals from Tesla. Therefore, an adjacent union striking against Tesla can be a substitute because Tesla doesn't have leverage to threaten them. It's worker solidarity.
Seems like extortion to me, so I certainly wouldn't want to put my career or my family in the crosshairs of a group that's willing to sink to such lows.
When the mafia demands protection money, it's prudent to fly under the radar.
When individuals decide not to do business with a corporation, it's a mafia, huh?
Corporations have to be forced to submit to society or they'll run roughshod over everyone as soon as they are able. They might even play nice at first, offering good conditions and pay, but that would never last. Learn from history.