Hey, why not just ask me?

It's my company's site afterall...
RE: PHP:
PHP is obviously an amazing enabling aspect for website development and publishing. It goes without saying that it's very powerful and very much in demand for most middle-to-advanced web developers. The key issue here for us was, "was it worth keeping on our system when certain unsavory individuals were abusing it in extreme ways?"
The answer: no, it was too much of a risk. When you have a mass-scaled free hosting system that's custom-developed, you can't have someone deciding they want to see what will happen if they try to delete other user's files using exploits possible through PHP.
So in these types of situations, where the positive (pleasing less than 20% of our users) is of much less value than the negative impact (risking losing all user data and having major security issues), it's a pretty easy decision to make.
We had a similar type of decision regarding data transfer/bandwidth. In the end, we decided to put an iron-clad cap on our advertised limit and provided the option for our users to purchase more bandwidth if they didn't want to wait until the end of their month's period to receive another 1 GB. Some users don't like this, but when you look at the benefits of keeping the overall system functioning in a much more reliable manner, it was hands-down the right decision to make.
BTW, other than a few minor complaints, no one really said much about it.
Maybe I'm getting the wrong impression here, but some of you guys seem to be coming from what appears to be a limited point of reference... it's only a small percentage of the public at large that can even create a website at all... much less to use PHP, mySQL, Perl, CGI's and what-have-you.
We approach website hosting from a much more middle-of-the-road scenario. I really enjoy the sites created by kids, grandmas, and folks from other countries who are just starting out. If and when they outgrow what we have to offer, they can and will move on... hopefully they'll remember a good experience with us and keep us in mind for our paid offerings.