... I've never known a five year old which has learnt PHP.
Exception handling adds robustness to your solution. It means that you can account for x and ensure the program does y, similar to how you'd use 'if' conditions in a script. It's a way to know that the program will handle anything you throw at it. Exceptions are an easy way to identify if something goes wrong and a easy/lazy way of solving the issue.
The security issue lies when the solution is programmed to display exception details such as a stacktrace with the user, this allows for users to get knowledge about the program and it's potential vulnerabilities.
Exceptions in almost every case will not lead to a security threat, the only time it will, is with improper usage of exception handling.