Like it or not, PHP is THE most popular language for developing web applications. And it didn't reach that rank without merits.
Sun pushed Java, Microsoft pushed C#, Google pushed Python in direct and indirect ways (but Google gave up on Python and created Go).
No big company spent a lot of money to push PHP (Yahoo started using PHP when it was already popular). PHP reached there because it had some merits in it.
- PHP is easy to get started and it helps people without CS background to learn it quickly and code apps to solve problems.
- PHP doesn't force you to use OOP unless you need or want that.
A musician named Derek Sivers who had no CS background created CDBaby website after following instructions in a PHP book. When Rails fanboys were making a lot of news, Derek decided to use Rails and scrap the original PHP codes [1]. He hired a top Rails developer and spent a lot of money (compared to the money - i.e. cost of a book on PHP - spent on his original PHP code) to rebuild CDBaby in Rails. The project eventually failed - time and money lost. CDBaby continued to grow rapidly and the site was powered by PHP codes. By telling this story, I am not trying to say Ruby and Rails are hard or bad. Ruby and Rails are tools just like PHP. The point I want to make with this story is PHP can get almost anyone up and running without much difficulties. Many people could get into business easily because of the ease of PHP. Just think if Derek had tried to make his first site using Rails! Probably, we would have never known the story of CDBaby.
I believe, the purpose of a programming language is to make it easy for user (of the language) to create solution instead of trying to prove the greatness (e.g. lot of features) of itself or it's creator.
Why is PHP easy?
PHP is easy because Rasmus Lerdorf didn't have CS background. He didn't want to create a language to have all the features and concepts taught/learn in a CS class of programming languages. Rasmus just wanted to create a tool to easily publish pages dynamically on web.
On the other hand, you can take a look at Java if you want to know how a language looks when the creator has PhD in CS and wants to apply all his knowledge of CS in the language. I am NOT trying to bash Java or Gosling, just trying to explain why some languages are created complex and difficult.
TL;DR: PHP is just a tool like Ruby or C. It has plus and minus points like any other language. PHP makes it easy to get up and running (even if you don't have a degree in CS). If you like PHP (after you try it), stick to it (because with PHP, you can get atleast as big as Facebook). If you don't like it, pick another language that works for you. And this last point is mainly for Snake lovers on HN : never bite a language (or users of that language) because you don't like or use that language.
[1] http://www.oreillynet.com/ruby/blog/2007/09/7_reasons_i_swit...