Solar panels 30-40 years ago were laughable as well mind you.
They were not laughable. There just wasn't enough of economical and environmental incentives back then to push for their mass production. Now there is.
Past performance (also known as experimental results) are the ONLY reliable indicator of future results.
So you're saying that the bulletproof way of making something complicated work is to employ people who did something simple that worked? I'm really not sure what your sentence is supposed to mean. I would have thought that future technological results depend mostly on inherent problems with the goals that we're not aware of yet.
If your main tractor breaks down you can still run the combine. If your disc needs repair, you can still plow or use the tillage unit. Putting it all in one machine would mean you are down when any one thing breaks.
I actually understand it more as unification in type rather than calling for people only having a single physical device. What prevents you from having two of them? Give it sane mechanical and electrical interfaces, and a single chassis could be specialized if needed (but not unless necessary).
No gay sex means the vast majority of the AIDS infections never happen.
It's good for Africa that they never liked gays there, otherwise they would have an AIDS epidemic on their hands by now. Oh, wait...
"The chain which can be yanked is not the eternal chain." -- G. Fitch