Lots of people are forgetting the context in which FastCGI was conceived: servers were expensive uniprocesser machines and enterprise servers with 2 or 4 sockets were relatively extremely expensive. All processors at the time paid heavier penalties for context switching and/or creating between processes. So the optimization folks building web servers were things like preforking the front end in Apache and/or preforking the middle end (FastCGI, WSGI, SCGI, Java App Servers, et al). The database was Oracle, or MySQL or SQLServer which was already multi client based. Also, in *nix land, the popular scripting languages (Perl, PHP, bash) of the time had a ways to go in reducing their startup times.