Isn't this more than just a simple commercial trade-off in that, as I understand it C41 doesn't develop entirely satisfactorily at the kind of low temps that B&W is processed at. So am I right in saying that while C41 cannot have its developing temp lowered to room temp, neither can B&W have its temp increased to anything like 38C even such high temps were the commercially desirable ones at which to process?

Or is it the case that, commercial considerations aside, the likes of Kodak could have developed a satisfactory C41 process at 20C and equally if the world was still B&W then then likes of Kodak etc could have and would have established a process suited to large scale labs at say 38C for a quick turn around and we amateurs would be struggling to find commercial chemicals that would process B&W at room temp because the "big commercial beasts" would have driven the amateur processor out of the market place?