PHP在try catch块中围绕整个脚本是一个坏主意吗？ [关闭]

On this page of the PHP docs, the first comment suggests a solution to custom error handling.

Johan writes:

Custom error handling on entire pages can avoid half rendered pages for the users:

<?php
ob_start();
try {
    /*contains all page logic 
    and throws error if needed*/
    ...
} catch (Exception $e) {
  ob_end_clean();
  displayErrorPage($e->getMessage());
}
?>

I was already going to use output buffering to avoid the half-render issue, but I hadn't thought of the possibility of surrounding the page render region in a big try/catch block.

In fact coming from a Java world, this kind of practice is more or less considered bad. But I know PHP and Java differ greatly so I'll ask here...

Is the practice above bad in any way (and obviously WHY is it bad)? Thanks!