Earlier quoted context omitted.
When you have incomplete information, there is another option besides saying things that are, as a result, probably mistaken: to wait till you know more before you express an opinion.
C'mon pg, this isn't that kind of forum. Posts are on the front page for a day at most, mostly a few hours or even minutes. You see a post, maybe read it, then write a comment. By the time I could get to know these companies, this thread will be long gone. If you like, I'll come sit with you for the next YC evaluations and provide my honest and informed opinions of the companies. There were only seven minutes for you…
IMO, the three major problems I have with your opinion are:
1) You assume startups should be tackling new problems. I don't know if you noticed, but "me too" companies win more often than grand new ideas with deep technical problems on the web. Google, Facebook, Zynga, YouTube, Groupon and the iPod were me-too plays.
2) You assume startups should be (or look) technically impressive. There are plenty of great startups that aren't really deep technology problems (until they need to scale).
3) You're looking at 3-5 month old companies, for the most part. Craigslist at that age was a mailing list in SFO. You'd look smarter if you were talking about things like "total addressable market" and "scalability of customer acquisition" than how impressive the companies look right now. Startups of this age are still mostly just potential.
The amount of time you invested in this screams "Troll" to me. The fact that you have had this happen enough that you say, "Usually, at this point, people tell me to just shut up, so that's what I'll do" seems to support that assessment. PG shouldn't be feeding you and neither should I, I guess. I'm mostly disappointed that your initial comment (devoid of any actual content) was upvoted by as many people as it was.