One point, which no-one seems to mention (or, perhaps think worth mentioning).... development time.

I find that I can code simlar web applications more efficiently (in terms of *my* time) in php than I can in perl. I learned perl and php together, and, in terms of numbers of lines of code, (in my local archve of "completed" work) have done about 50% more perl... so that's not simply because I've worked in php more.

PHP is limited, but I don't think that this is always a bad thing.

For myself, if it's displaying on the web, and is quite simple, I use php. If it's not suitable for the combination of my skills, and php, then I'll figure out how to do it in perl. So far, this combination works well...... for me.