Mostly I'm a Python fan but for websites PHP is just 100% easier for me because I have a framework I know well (KohanaPHP) and years worth of snippets/experience to use in prototying sites. I bet I can code a simple site faster in PHP than Python.
As to why PHP isnt discussed much on here: well I will hazard a lot of people take the same approach. We love exciting stuff in Python, C and Ruby (well, not ao much ruby for me :P) but PHP is our grab-it-and-run language. If someone knocks on the door and says "make me XYZ website in 2 days" we will probably pull out the PHP.
Nothing exciting and new is really happening with PHP - it is doing what it is supposed to do: help us produce dynamic websites fairly quickly with little fuss. So we can get on with the real job of hacking in Python (or Ruby or C or..... etc.) :D
I could be wrong :)