Or by being told what they can do and how much they can make based on seniority, not skillset and talent.
Wouldn't you like to have some kind of transparent review process for iPhone apps? Or an agreement that the Twitter API will be available for 5 years? Good luck negotiating that on your own.
Why not? Unions and union members are extremely rational. Are you suggesting that developers would be less rational?
I'm reasonably anti-union but I'd vote for seniority as a union member. It elevates my salary at the expense of people who don't get a vote (new people). It lets me slack off. And, for folks in the bottom half, it's a salary increase.
> Wouldn't you like to have some kind of transparent review process for iPhone apps?
That doesn't have anything to do with unions.
In other words, a developer's union would want to be a lot less like the United Auto Workers and a lot more like the Screen Actor's Guild.
Every engineer thinks they are better off without a union because they are above average and would be pulled down by joining a group of average workers.