I thought everyone here at HN was ....well, to put it simply, less negative. I mean, YC is all about doing new things, revolutionary or even just evolutionary changes to existing products or markets. Thinking outside the box. Changing! (etc etc ad nauseum). Why did this thread devolve into "it can't be done" or "it can't be done that cheaply" or "it's just product x" or, finally, "its just revision n+y of product x"…
I think it's an awesome, exciting project that the world wants to happen. But if it turns out that the original timeline is skewed heavily toward irrational optimism, it may be demoralizing to those involved to have their expectations repeatedly quashed. However I may be wrong here, because if the supply chain company that's involved is being realistic and has experience, I may be the one who is off-base about the timeline.
(I posted more details of my experience on the main thread).
I agree with you that a lot of comments on here are negative without adding any value, ie. no new data / insights, just content-less, emotional pessimism.