I think they think of "closing an app" as closing its windows, which on Mac does not always "Quit" the app.

Right, I see. That is the traditional behaviour but there’s lots of apps that don’t do that, and closing the last window does also quit the app.

	▲	LoganDark an hour ago \| parent [-]
		That's a perfectly acceptable practice for apps that only ever have one window. For document-based apps or apps that have multiple windows, usually the convention on Mac is for closing the last window to not also quit the app. But of course there are exceptions in both directions, it's not a hard and fast rule.