Who says CGI/PERL is obsolete?

Some say CGI/PERL is slow.
Some say CGI/PERL has security problem.
Some say CGI/PERL is phased out by PHP.
...

But there is still one "BIG" website that is still using CGI/PERL until today. Have you seen this:

https://www.paypal.com/my/cgi-bin/webscr

If CGI/PERL is not good, why is PayPal still using it until today to deal with large sum of credit everyday?
UPDATE (April 4th, 2016): It has been six years since I posted this comment about PERL's popularity. But I now would say PERL is already obsolete for me as PHP is far well supported by the developer's community. PERL's support doesn't seem to exist anymore as most developers are now using PHP as their favorite scripting software running on the server side. Whether Paypal is still using PERL, nobody knows as it is important for website like Paypal to refrain the visitors from knowing the type of scripting language it is using. Even the question now is whether PHP will be phased out by free online web editors such as Wordpress, Drupal and Blogger.