PHP-5.3, phar extension - is it necessary by default?

In PHP-5.3, the phar extension has appeared , and in recent versions it is enabled by default. However, after I observed the following picture: a segfolt when using the standard function is_file () (which is in fact a direct consequence of the fact that I installed this phar with PHP) - after that I firmly thought whether this extension is necessary set by default and would it not be better to put it, on the contrary, only on demand.

In short: an extension declares “interceptors” - interceptors - for calls to certain functions that are not at all included in this extension. This behavior, for obvious reasons, is undesirable for many - these are extra brakes, extra bugs (as the above link to bugs.php.net proves).

I can add that one of the leading developers of PHP has already spoken in favor of not including phar by default. What do you think?