I've worked in web dev for my entire career, and at no point have I thought to myself "Gee, those devs in gaming have sucky pay, sucky job security, and they have to deal with crunch all the time, so I should accept a bad offer because it could be worse." That's not how people think. We all fight for the best we can get for ourselves. Starbucks "partners" (staff) don't want to be the best of the worst if that isn't a fair deal for them. Who would?
I am barely disagreeing with you, but negotiating the best deal has nothing to do with fairness. They don't want to be best of the worst, or whatever, even if that is fair. They should get more if they can, of course. (What does fair even mean anyway, because it's not like Starbucks, Inc. is some sort of comparable peer.)
Sure, but a key part of negotiation is just quitting and working somewhere better. If there is no somewhere better than your leverage isn’t that great.
And if your leverage isn't that great you should unionize.
True, but I wouldnt expect better than other employees who have more leverage.