I understand your point but disagree. According to forum users, Bria 5 hasn’t worked under the beta version of High Sierra. So they didn’t release the new version for High Sierra.
Version 4 was still being sold only a few months ago. There are many users who bought it before June when Bria 5 came out who now either can’t upgrade their OS (and remember, it is a maintenance release, not a different operating system) — without having to pay for a new version of Bria — or an alternative — less than a year after they bought it.
Do you really think it’s fair that they sell software with less than a year’s useable life on the same os? If they can make 5 work with High Sierra, they can make 4 work with it.
But they have chosen not to in the hope people will simply pay another $30 or so for Bria 5. Well, I won’t be. And lots of others have voiced (no pun intended) the same opinion. And they haven’t just lost the $30 for my licence but others and every future purchase we would have made from them for other staff.