GAF talks about it as like "they need to form a gamemakers union" but it wouldn't be that, it'd be like Hollywood, designers, writers, programmers, artists, sound guys, etc. all negotiating separately and against one another. Only with companies that won't actually need anyone in the unions.
I'm actually quite reluctant to consider most of the film guilds to actually be unions in terms of how we would think of them for most workers much like those in the sports leagues. For reasons you mention, plus how often they waive their rules effectively so as to not alienate the stars.
The tech industries have a really strong notion of you being able to say "fuck this" and go start your own thing. Or stuff like programmers who would never abide by some union work rules. Even in "established" industries, Intel's origin is guys who split off from a split off from a special division that fled one of the largest corporations on Earth.
Could they still form unions, yeah, of course. But, I mean, who is going to want to join them and give up their personal negotiating power? Consider the tech guy who ditched Crytek to join id replacing Carmack, I imagine he got a hell of a deal that no programmers guild would have negotiated across the industry. Either that or it'd be like cases with the big directors in Hollywood who opt out of the guild. A union made up of EA, Activision and Ubisoft lifelongs/grunts isn't going to have too much negotiating power in the industry writ large.
