"Obviously, performance was a big win. The website felt like it was running on local machines, bringing a dramatic increase to speed and lower latency across the board. After the switch, at first the load on our cloud servers was so low that we thought the website was down! Switching from PHP to D meant we could cut in half the instance size of each Amazon AWS machine in our cloud. And these machines are still underloaded. Our database cloud was highly affected by this too. We now use one quarter of its original computational power. All of this brought an instantaneous and dramatic cost savings, down to more than half of what our costs used to be."
I'm willing to bet they didn't even try a single one of the many possibly optimizations they could have used and actually stay either in PHP or a subset of PHP. It's so much easier to win your argument with a strawman, not to say there aren't cases where D is, in fact, better.
https://stackoverflow.com/questions/1408417/can-you-compile-...