[nmstoker]

With such a huge spectrum of kind of software, what applies in one kind won't necessarily be so for another.

The heartbeat argument is an obvious case. It's the same reason people look at the UI "chrome" in the screenshots in Android Play Store - if the battery indicator is from Eclair it doesn't built confidence it'll work in Nougat!

But that may apply less to a more minimalist utility (eg a command line tool)

Merely to update it so that you formally confirm that this version was tested on newer systems may be valid in some cases (although one could merely update documentation in many cases for that).

And then there is the dependency argument. Where a tool directly contains underlying packages, it builds confidence the developer won't get stuck too far behind current(ish) versions (with the greater risk of it becoming abandonware). Where the dependencies are external (ie up to the user to have installed) you do not want to be stuck on some old version, as other tools may move on, even if this super-stable software doesn't feel the need.