The video game industry is the new movie industry -- except nobody is unionized. The film industry is notorious for this crap as well; look at the Sausage Party controversy for a recent example. Honestly, a programmer on a video game is not much different than a camera operator, a film editor or a VFX engineer. Sure, you need quality work in those areas to have a good product, but great work in these areas can still be submarined by a terrible concept (ahem ScarJo's Ghost in the Shell).

And really, can you blame them? Revenues are largely based on the work of the producer (marketing / promotion), the director (overall tone / quality) and the acting talent (big names = box office draws); the folks behind the scenes get screwed over (or they would if they didn't have unions ensuring some long-term consequences for producers acting in bad faith).