i said "leverage their labor" since, you know, labor is in fact a commodity
Their "labor" has no leverage. It's an unskilled job. At least so far as most retailers are concerned. If anyone can do what you are doing you have no leverage.
also it's not very easy to leverage your labor when you're a wage slave. minimum wage isn't a living wage.
Not arguing that. I would like to see retailers hold their employee's to higher standards of work/customer service/hell hygiene in some places, and by doing such increase the value of their employee's and pay them higher hourly wages. See: CostCo. Store is always clean, workers are friendly, workers don't look like meth heads, workers are knowledgeable, etc. Usually none of those things apply to your average Wally World worker.
the point is, i don't see any consistency when you can say both "yeah sure they should be able to fight for higher wages" and "they should just stop bitching about working on holidays because they knew what they were getting into"
These are two completely different things. My wife is a heart surgery nurse. She was on call "working" all Thanksgiving and the following weekend. It's part of the job. If you work retail, especially Walmart and the like, expect to work some Holiday time that 9-5'ers use to shop for presents and Black Friday deals.