Safe mode died off a long time ago. Yet, people complain you are insecure if you have it off... Security comes from server management, not PHP features on and off.
Yes, we used to run PHP in safemode on all our shared servers in 2002, Buddy safe mode died a long time ago.. and in some cases i heard makes your server more open to attacks.
Just a heads up to all those running in SafeMode - when you upgrade to PHP 5.4 you will no longer have that option. For security reasons, Safemode has been removed.
That should pretty much show the light on why nobody recommends to use it on the older versions
If you like web hosting to be functional you cannot afford to run a shared hosting environment + safe mode. This will break most of the customer's PHP scripts.