No. As a software editor, you either support an OS or you don't, according to 1/ your customer base and 2/ your abilities. Given 7 still has a significant market share, wheras 8 and 8.1 don't, there is nothing else to consider here. As I said, all that matters is whether you want to lose customers or not. Everything else is wank.
Windows 7 is past End of Life. Anything else can be endlessly argued and debated and is indeed wank, though it does appear almost all relevant developers seem to follow suit.
That was not the debate here (at least not in my reply, relative to what nigelwright7557 decided, and which some found odd.)
Again, as a software editor, your only concern is whether the OSs you decide to support have a significant market share or not. Else you lose customers. Simple as that. And if you're willing to lose customers just to make a point ("I told you it was obsolete, dammit!"), that's your problem, but usually not a wise decision. You may decide this if you don't have the resources to keep supporting it. And here, it exactly looks like what nigelwright7557 did. And again if he had to choose between dropping 7 or 8/8.1, the market share figures make the decision pretty obvious IMHO.
Since Windows 7 still has between 20% and 25% (depending on the source) of market share among Windows users, it IS significant enough to decide, as a software editor, not to drop support for it.
And knowing many engineers, I'd even venture that this % is higher among engineers themselves, so if you sell software for engineers, well. That's definitely significant.