I actually see quite a bit of the same mentality here. Anything deviated from the main stream of the latest fad will get downvoted. There's little appreciation of diverged opinions or opposite views.
I look back at my comment history and see that generally speaking, if I say something relatively thoughtful, almost without exception it doesn't get downvoted into oblivion. Were I insulting, rude or uncivil a different standard would apply.
The same simply can't be said for proggit. Proggit has gone the way most mature forums go: elitist, dismissive, intolerant and reactionary. You saw the same thing on Usenet (eg comp.lang.c) in years gone past (if you're old enough to remember that).
There is a certain personality type that seems to float to the top of such dank, stagnant pools of water. I call such people toxic. You see it on forums, in open source projects and the workplace. Such people seem to be attracted to the ability to exercise power without actually contributing anything (although they're convinced they are contributing). Once a certain number of such people are entrenched it's very difficult for any such organization to ever turn itself around rather than fade into irrelevancy so much effort needs to be spent simply keeping such people away from the controls.
Much of Zed's famous anti-Rails rant revolved around such people (a classic example being someone writing security code assuming there were 30 days in every month).
HN is not that way at all and any stay on Proggit should tell you how far off HN is from that in a very short time.
I'll show two of my encounters as a limited data point to illustrate that HN is not far from getting to the level of Progit.
In one post about shebang (#) being used in Facebook and Twitter, the discussion was about crawling Ajax pages. I asked a question on good practices to make a Ajax site crawler friendly. It got downvotes! I was truly puzzled. The question was purely technical, non-controversial, within the topic, and extending the discussion. Yet, there were people (long timers with downvote power) trying to discourage it. They were acting exactly like toxic as you described.
In another post about Joel's statement of SO being more scalable than Digg, people were giving this and that explanation but ignoring the obvious elephant in the room - .Net was faster PHP. I made that statement and got downvoted to oblivion. Of course people here hate Microsoft, are into dynamic-type languages, and prefer open-source but a technical fact is still a fact. This just shows how narrow-minded people here are who can't tolerate diverge approaches to problems.
Oh well, if they want it to be a toxic playground, they get it.
I don't think that you're accurately representing the state of affairs.
At the time I'm reading it, your second comment (http://news.ycombinator.com/item?id=1799442) is neutral at 1 point. That is not a symptom of people acting "toxic" and trying to "discourage" you. It was a good question, but nobody seemed to know much about it, so it just sort of sat there.
Your first comment (http://news.ycombinator.com/item?id=1787833) is at -3 points. Unfortunately, as it's five days old, I can no longer put it at -4. You stepped into an admittedly poor discussion about specific reasons why SO might need less servers than Digg, and posted a flamebaity generalization with absolutely no support; you didn't suggest a reason that .NET might be faster than LAMP, nor any evidence that it might be faster, or what it might be faster at. You just dropped a one-line load of an opinion and left. I absolutely am on board with being maximally toxic and discouraging toward the comment you made there.
The 2nd comment (http://news.ycombinator.com/item?id=1799442) was downvoted. I saw it after I posted it. It was brought back up by others upto 1 later. Tried as I might I just couldn't understand the rational of the downvotes. I could only attribute it to the Reddit-like behavior where every submission has 33% downvotes, which is why I'm saying HN is heading the Reddit way.
For the first comment, it's pretty well-known that C#/VB.Net is way faster than PHP/Python/Ruby in raw performance. Benchmarks after benchmarks have shown that fact. Often it's just a matter of bringing it up as a reference in discussion. I don't want to prepare a benchmark for every statement I made.
I've seen plenty of opinionated single liners got plenty of upvotes, admittedly those stated the popular views, so single liner is not a good reason for downvote. But nevertheless I'm not into a popular contest. If HN can't tolerate diverge view/opinion, that's its loss.
