PHP hate is often a knee-jerk reaction here on HN. It's a language that has both some very cool features and some legacy baggage it carries around - and it's absolutely possible to use it for good (and to use it well). I think PHP's image problem comes from the perception that there is some very low-quality code out there, but it's definitely mainly an in-group coolness issue.

It's one of those things that (negatively) surprised me about Hacker News, actually. People go around and unproductively bash each other's programming languages when they could use their energy to elaborate on the stuff they actually like. The group consensus seems to be that Lisp is the best thing a language can hope to be; and since very few people actually develop in Lisp-likes, they fall over each other to claim the next-best place in the All-Time Universal Programming Language Hierarchy(tm).

I believe the origin of this behavior might be a somewhat mistaken PG essay[1] implying that all non-Lisp languages are "Blub", which is a synonym for "sucky, powerless, inferior language".

[1] http://www.paulgraham.com/avg.html