This is weird. I am sure “Die Terranauten” discussed this topic at length (one of the main ideas was that a plant based galaxy wide civilization had been one of the first to ‘conquer’ space). However the series ended in 1981.
I guess the distinction between scientific hypotheses and scifi that extends beyond well understood science is that you have to have scientifically rigorous reasons to think the hypothesis might be true. So not mere notions, e.g. there is no cold fusion reaction hypothesis anymore.
I guess it simply shows that atuhtority is the most important quality you need for breakthrough ideas and whether you are doing science or writing fiction is not so relevant :)