In a recent post to his blog Kenny Katzgrau talks about why PHP was a ghetto (both on the quality front and the public perception) but how things have turned around and the language is being perceived as stronger all the time.

I was talking with the Co-founder of a pretty cool start-up in DUMBO the other day about why the non-PHP development world generally has such disdain for PHP and the community surrounding it. He brought up an interesting point that stuck with me, largely because I hadn't heard it before. [...] He didn't say the actual language was poor - he said it was the general culture surrounding the language, which is usually iconified by a language's founder, that seems to encourage bad practices. That is, PHP code bases tend to be hacky and unmaintainable.

He goes through a few things in PHP's past including the influence that Rasmus Lerdorf has had from the beginning and how the "pizza-faced adolescent years" of PHP have been a big part of the problem. Because of its past, PHP had been considered a "ghetto" but with recent improvements like encouragement of coding standards, full-stack frameworks, great unit testing tools and the same low barrier for entry, the language is gathering its strength and moving away from its past into something new.