Think of it in terms of something like the second amendment. Unions are similar to weapons in that they're the only real limit on the power your management has over you. The last line of defense, if you will. Without coordinated response provided by unions you _can't_ make your employer change their labor practices. If they want to make you work 16 hours a day for the same pay, there's nothing stopping them.
In an industry known for abusing its employees (which, BTW, does not extend to software engineering in general, in my opinion - software engineers are treated well almost everywhere else), you _need_ pushback to end abuse. It's as simple as that. Even if unionizations fail, they still serve as a signaling mechanism - if things get bad enough, they'll start succeeding, and that's the outcome employers would like to avoid. The solution is simple: they should pull their heads out of their collective asses and start treating employee abuse as a real problem. If there's no downside for them to not doing this, they won't do it. It's as simple as that.
