What do you think of this argument against raising the minimum wage?

[All Along The Watchtower]

The argument goes like this:

A business employs some people at $10 an hour (which is the minimum wage in this scenario) and other workers at $12 an hour. These are the two lowest pay levels at said business.

Now, the minimum wage gets raised from $10/hour to $12/hour; what happens to the employees who were paid $12/hour before the minimum wage is increased? Their wages won't be increased (or so the argument goes) any time soon, and wage increases for them will actually be delayed, yet they have seniority and experience over the minimum wage employees.

Is this a valid argument?

[All Along The Watchtower]

That strikes me as being not so much an argument as vague concern trolling that implies that we should feel nonspecifically affronted by the possibility that it contemplates without actually explaining what it's attempting to demonstrate.

So in other words...

Whatever?