Based on what exactly? A cursory google search shows the average income there is 46.5k or $22 an hour
A quick skim through job listings shows even part time retail (generally some of the lowest paying jobs in the job market) are starting out above the $12.50 mentioned here.
Blue collar manual labor in warehouses or factories generally starts at a much higher rate than retail. The Dole foods warehouse worker listing for example shows a starting pay of $17 to $18, which is relatively close to what starting pay for lower level warehouses looks like out here.
It does not appear that $12.50 is a market rate for that work in that area or anywhere near it. And again if the company is trying to hire on people below market rate that's not a staffing shortage. That's a company lowering the bar over and over, and when they've finally lowered the bar so low Americans won't touch it anymore it's time to import from the third world.
It's exactly what we said was happening.