No, that's not strictly true. If you have min & max servers fixed at the same value and the max requests per child set absurdly high, you won't fork much if at all under heavy load. Pre-forking can result in a lot of forking and requests being blocked while you fork if a) you have a surge in traffic and b) your min servers isn't set high enough to cover the surge or alternatively c) your max requests per child is low enough that you are constantly having processes exit.
> I never claimed forking is expensive. I said it's expensive compared to an event loop.
Agreed, although that's kind of a meaningless statement (an event loop is something you go through on a per-request basis), and misses the real problem with the multi-process model: virtual address space for each process.
> It's not a technical argument but a religious one. Nginx is good enough. Apache is not.
Umm... that sounds like a religious argument in its own right. Apache is certainly good enough for plenty of people, and more importantly with all the dynamic content on sites, the web server tends to be a pretty unimportant factor in the performance of many sites. Apache brings other things to the table which are often valued for projects, and there is no reason that needs to be considered a "religious" decision.