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.
Or by being told what they can do and how much they can make based on seniority, not skillset and talent.