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

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.