I'm actually glad this thread got pushed down, so maybe some actually informative discussion can rise up rather than an analysis of how minutely the people behind this screwed up.
Sounds like a guaranteed way to fail.
If the product does not provide a decent ROI then you are right to dismiss it.
Your postulation is unwarranted, by the way, since my posts have been going up and down based upon their depth in the thread. The top comments have been upvoted more than the lower ones, and the lower ones have actually been muted somewhat. I would actually suggest that people are reading the thread and voting appropriately, and probably aren't making it deepest into the thread.
Your sweeping characterization of mindless Hacker News voters acting by whim is disconcerting, to say the least. That we're so fixated on the voting here when karma is absolutely worthless is equally annoying. I am, however, intrigued by the shift from very light gray back to legible that has taken place on his comments since the beginning of this meta discussion (starting with ww520's remark); there might be something to what you're saying, which is that people are acting based upon what others are saying -- that's troubling.
When you're reasoning backwards you're on thin ice because it's easier to let a logical fallacy through as you start assembling your "facts and assumptions" in the rush to make your point known. You can "win the battle" (by being quick) but "lose the war" (by being wrong), and when I catch myself doing it I have to either cancel the post or put extra effort into it to make sure I have a valid argument(and often, after doing enough research, I don't, or I have gone too far outside my domain to know for sure).
Forward reasoning usually results in very straightforward critiques like "I used this but it was not appropriate for these situations..." or "it completely failed in this case..." or "it turned out to be unnecessary for the project I was on." Kevin's posts(both the initial one and follow-ups) get muddled because he has to weave together several minor points; as each successive rebuttal comes forward, so does his target, so that the final opinion remains the same, even though by the end he's reduced to "they're lying."
(A good example of a game developer who has put some serious effort and notetaking into finding ROI on a new tool is John Carmack and his forays into static analysis.)