alt Hacker NewsPart of being in a union tends to be lawyering up and "nailing down" exactly what everyone's duties in detail and what fair compensation might be, and what terms / conditions might be etc.
Personally I don't think they're a great fit for the software industry where the nature of the job and the details are continuously changing as technology evolves.
That's not an intrinsic part of being in a union, just a particular way they have been implemented in US.
The fundamental point of the union is to be able to negotiate as a group. That is valuable regardless of the industry.