IMO, if the kit manufacturer had sold a decent product, they probably wouldn't have gone Tango Utah. However, I also understand that businesses take a lot of work and long hours, so it's entirely possible that some owners just got to a point in their lives where they just lost their enthusiasm. Lives change, markets change, supply costs change, and all that stuff can enter into a company's closure.
A lot of those old kits have been saved by enthusiasts doing CAD drawings off the original kit or plan. Is it better to not build from those plans, or let those old designs vanish? If you buy a plan from AMA's plan service, do you think AMA will send a check to the late designer's family? For the record, if I was to build a Bob Hunt "Caprice", I'd get the plans from him, but would likely change the shape of the fin...and I'd still write Caprice on the wing and still enter it in Classic, because it'd be completely legal to do so.
Steve