I wasn't around for version 4 upgrade, thankfully i guess. To be fair, with current version 4 my experience has been very positive and software stable. That however doesn't change the fact that paid public software used by hundreds, maybe thousands? of people appears appears to be released in beta stage for users to waste time working out bugs. I don't agree many other software being broken on the first release, i don't recall last time i had upgrade issues with anything, either personal or at work, feel free to quote what other software releases had these critical upgrade issues.
As for the common sense, i believe industry standard is that public versions released are alpha and beta tested and ready for public to use on the first day.
Maybe next time you
BlueIris should call initial release "beta" and ask users to work out bugs, i'm sure there would be a lot of volunteers to help out, rather then pretend this is some sort of "common sense".