To me the headline says it all. Those workers, being in demand, asking for higher wages. What about our profits! We need a level of desperation in our work force, at least that caused by 4% unemployment, if we can expect to maintain the wealth gap that has been built up over the last years! (If it's not clear from the above, personally I am in favor of low unemployment and higher income equality.)
In reality it's mostly just math in action.
And, of course, headline writing doing its job of making you engaged (angry).