WP Twice faster without call to this function

Hi

I had made a little benchmark theme for wordpress (it displays nothing), and some functions that displays enlapsed time since wordpress core loading start (you know, like a stopwatch).

WordPress core takes about 400ms to load on my computer (iMac 2007, MAMP PHP5).

But when I turn this line off (/wp-settings.php, ~ line 650) :
// load_default_textdomain();

WordPress core takes only 160ms to load !

I’m french, the only inconvenient of this « optimisation » is that the translation of the admin panel is disabled.

So I would like to know if it’s a good idea to delete this line, can it make some errors/bugs ?

Thanks