Website Development Screencasts and Podcasts

I always wonder why the hell people who write and compose screencasts, blogs, podcasts and other tutorials regarding web development on Mac OS X always begin by installing MAMP. Mamp is the Macintosh, Apache, MySQL, PHP/Perl/Python stack application. OS X has shipped with Apache and MySQL already installed and configured for quite a while and PHP already has an OS X package available that integrates the whole system nicely.

Why increase your bloat by reinstalling it all? It bugs me.