It proves that the technologies are capable products at the most massive scales. Do you have evidence to support that Facebook, Tumblr, or Etsy would have been better off had they chosen different technologies (of course not)? Or that they made things more difficult for themselves? How would Facebook be improved by PostgreSQL? At scale, data is so massively partitioned that the fact that you don't have windowing functions is utterly irrelevant. I hate PHP as much as the next guy, but the facts are that it gets the job done. And that, in business, is what matters. The angst on here about MySQL is unfounded and is largely a symptom of groupthink.
I said capable, not awesome, or cutting edge, or the only thing you'll ever need, or the best thing since sliced bread. Capable is very different from your obviously flawed analogy. Windows 3.1 and the original Macintosh were successful at the time because they were capable products at the time which have evolved into the good, but not flawless products that exist today.
The groupthink MySQL/PHP hate here implies these are terrible products which only a moron with bad taste would use, which is demonstrably false when you look at the choices made by those using them.
I don't see any conflict between the notion that PHP is a turd of a language and that it's perfectly adequate for building something major. If you're willing to spend years holding your nose. Or if you have little aesthetic sense. Or aren't experienced with other languages and don't know any better.
As far as I'm concerned, PHP is the Bud Light of programming languages. Popular and perfectly adequate for a large audience, but definitely not a sign of taste and discernment.
Thanks, papsosouid. Facts are much more useful to discussions like this. It still doesn't change the fact that PHP is capable of running the most trafficked sites in the world (side note: I don't like PHP, either. I just hate haters who can't see the world in shades of gray). Having heard Facebook engineers speak about MySQL many times, I have not seen any inclination that they are dissatisfied with MySQL as a platform choice. (And please, no one reference on that utterly BS article published on gigaom.com)
You aren't supporting your case at all. I said "just because you can accomplish something with bad software, doesn't mean you accomplished it because of that software". And you responded with "it is possible to build big things with bad software". Yeah, I know. That doesn't make the bad software good though, which was my point.