That makes sense to me. Sites really should be designed to look good on mobile then adjust them so they also look good and function well (often with additional, lower priority content) on larger displays.

For a few years I have used Bootstrap as a starting point, and as a refresher I am taking the edX Bootstrap class right now. The course emphasises a mobile first approach. In addition to making web dev easier I also really like Bootstrap because it is so common that users instantly know how to navigate and use a site. A nice way to show content.