Java bites. I write both Java and PHP. PHP is a LOT more fun. Hardware is cheap compared to developer time. Java doesn't make a lot of sense on the server anyway. Why do you care if your server side code is portable. It won't be anyway, more than likely, even if you write it in Java with all of the configuration involved. How often are you going to move your code from server to server?
Maitainability is DIRECTLY related to how much code you have to write to print "Hello World". If the chosen languge requires ten lines (like Java) to accomplish this, it's going to be a pain to maintain.
The things that matter are how long it takes for your visitor to receive the information they requested from your site and how long it takes you as a developer to deliver the functionality that your boss or client wants.