Theirs is a project to attract kids and teach them some skills, hopefully get a few to continue, designed so volunteers can pay out of pocket. It becomes a trade-off between the cost of materials and doing a project. If just a few continue growing food though, they can figure out some partnership or a way to raise money to replace it.
I am investigating ways to give away raised bed gardens to get more food being raised in backyards, and thought something like this might be a nice addition for start-growing volunteers.
For individuals, or if money isn't an issue, I completely agree with you, and I intend to do that for my smaller one. We live in a Zone 4 or 5, depending on the year, so I expect to get some use out of it.
On another site I saw them use double-sided sticky tape that was designed for this (stickier than Lowe's tape?). I need to read up on that, should be easier on the plastic with staples, after the plastic is pulled over the structure.
It's like a big erector set, but with big people toys
And the dome brought back memories of the 70's.
I would like to see all that innovation going on again.
And thank you very much for the links.