Federal Minimum Wage of $15?

The article tends to already align with my thinking so excuse my digression:

What is the actual reasoning behind reaching 15 an hour that precludes landing on 20 or 25 an hour?

To me this seems like such a feelings (is-ought sorta deal) thing that I am convinced I'm missing the systemic arguments here.

it's the same logic that stops you from from taking an entire bottle of aspirin when you have a headache.