The dot com bust was a bit of a perfect storm, lots of people weren't needed because Y2K was over, lots of dumb ass startups with no product and no revenue disappeared and finally 9/11 gave everyone an excuse to chop heads because the economy was surely tanking. The first two were going to happen no matter what an the third just amplified the situation. Through all of it there was still hiring, the week I got hired the company that hired me laid off 12,000 people.