Bummer!
Have they thought about copyrighting the plans and selling the instructions?
Homemade boats are like homemade cars or airplanes. If you make it, you can use it in most cases. Here in Missouri, I can take about anything I want and call it a boat and float (or sink) in it. We have a "Cardboard Boat Race" here every year. As long as you don't put a motor on it, you don't even have to register it.
I think they can make a DVD with the material list, patterns, and a video showing how to make the parts and assemble it, put a big long drawn out and boring disclaimer on it covering all known and unknown stupid stuff that people have done, or will ever do, and sell it for $25 on a website.
I'd buy it!
I really would. I like that little boat. It's perfect for what I'd want to use it for, which is a little dinghy to paddle around the coves in the lake on a calm day.
But you're right. If it was sold at Wal-Mart, someone would take it out in Lake Michigan during 5 foot swells