I think the point is that yes, this technology as it exists today is only commercially viable for some products which are only appetizing to a wealthy elite market. But that's an advantage, it provides a stepping stone. The profits from that can be pumped into R&D to further commercialize the technology, and build a commercial ecosystem. Perhaps at some point in the future the technology will be applicable beyond the simple crops planted today.
In Tesla, the roadster not only proved that electric cars can be good, but that they can be better. Though not everyone can afford a roadster, enough people could and that car was a launch pad for R&D of electric car technology, manufacturing (which it turns out is truely the hard problem in building a car company) and consumer desire.
I absolutley agree regarding the development of EV tech. The main reason I have my doubts about tesla fulfilling all the visions people seem to have about them is manufacturing. This is a well solved problem for existing car makers, so tesla's real value would be as a brand. I dont see batteries being the USP, same as I don't see engines right now, no matter what certain engine fanboys say. Also, Panasonic is usually not getting the credit it deserves when people talk about Tesla's battery tech. As long as Elon is at the helm and manages to sell the vision peopl what to hear, tesla should be fine so. the last two years taught me as much.
In Tesla, the roadster not only proved that electric cars can be good, but that they can be better. Though not everyone can afford a roadster, enough people could and that car was a launch pad for R&D of electric car technology, manufacturing (which it turns out is truely the hard problem in building a car company) and consumer desire.