FastCGI is language-independent and like cgi can serve all languages, but setting up nginx with fcgiwrap and spawn-fcgi is only used for serving Perl. Almost all tutorials and instructions use this method for Perl-FasctCGI. For serving Pythong scripts, the dominant method is uWSGI.

Is there any limitation for using FastCGI for Python that it is not usual? or the reason is merely that uWSGI is better?

If it is only better, how much? Why there is no such system for Perl?

According to my tests, nginx FastCGI is able to fairly serve all scripting languages. Is there a problem that may happen at heavily usage?