The author seems to assume that every minimum wage person is capable of more difficult work.  Our warehouse has 320 general labour positions over 3 shifts.  Most of them are unemployable in any setting other than general labour in a warehouse - in our case, mostly because their English is so bad.  We will be reducing the workforce to 280 in January, and the least employable (oldest, weakest and worst English) will be layed off permanently.  Most of these people aren't worth the $12 / hr they make now, let alone $15.