"It doesn't even have object inheritance! And what do we need all these concurrency things for? Windows has only had preemptive multitasking for a year, and multi-core is still a decade away."

And yes, at first, it was dog-slow, but it was the kind of dog that you could drag behind the barn when things got out of hand. Apache+PHP or (yuck) classic ASP would just bring the whole machine down on a bad day. This isn't much of an issue today, because first other languages/runtimes improved, second we have more robust monitors in place, and third the "machine" is more often already virtual and more easily recyclable.