[m132]

Because it comes with a lot of overhead and, unless for some reason you really need every of those processes to have their own address space, set of privileges, file descriptors, etc., there's no point in wasting resources repeatedly setting those up only to tear them down milliseconds later. Running the same workloads in an nginx-style process pool usually works better.

[sanderjd]

I see what you mean now. I agree, a sustained workload of creating many processes very quickly is probably not a great idea. But it's also useful to be able to spawn that process pool (and any number of other use cases like that) efficiently.