Rephrasing from my original comment: Because Google worried about a very supply-limited audience (tech workers, including related non-programmers). Most fields, the ones paying their employees far less and with far fewer perks, don't share that restraint. If these other fields had their current crop of (non-unionized) workers get disgusted, the companies would just get different employees.
There's no shortage of companies with various abusive practices that remain in business. Arbitration agreements, micro-management, strict controls over things as simple as bathroom breaks, even riding the line on wage-theft. I'm very glad to see this particular change, but to say "Google's programmers demanded change and got it, why don't you get with it, un-unionized cashiers at S-Mart!" overestimates the influence of those workers.
So, would you say it is particularly repeatable in this industry? I.e. that while those other industries need unions due to lack of leverage, this one may be different?
(of course one instance is too small of a sample size to support either direction on its own)
I'm hardly qualified to have anything but the most grossly informed of opinions, but yeah, I'd expect that in the current environment most tech-area (i.e. Seattle, SF, etc) devs can and should demand improvements and be able to get them without requiring unions (which is not the same as saying unions aren't needed. Look to games dev for examples).
