Well for starters, the person above was pretty explicitly NOT advocating for reliance on third party libs, and perhaps more importantly, they were not in any way suggesting reliance on closed source software. In essence, diametrically the opposite of everything you were talking about.
I think your confusion came in their phrasing of not relying on “labor product.” I took them to mean, not relying on people committing their free labor to sustain FOSS. I think you must have read that as not supporting FOSS.
Also - not constructive? But you’re the one that’s being negative.
I think they are right. You took the exact opposite of what they said and “corrected” them for it, which is irritating as hell. And now you’re doubling down, which is worse. I would be irritated too!