The perl porters aren't "a bunch of irc burnouts" as you claim, they're smart guys with a long-range plan for what they're trying to do with the language. That plan apparently doesn't have ithreads in it, but we hope they come up with a better version of threading.
Now the fork thing is the first actual argument you've provided, but
On some platforms such as Windows, where the fork() system call is not available, Perl can be built to emulate fork() in the Perl interpreter.
Maybe building with fork emulation isn't as common as I thought, though? I don't know.