I have a student loan to pay off that's around that amount, and I was employed at a web startup right out of school making a whopping $42,000/yr after taxes. California rent is $1,000/mo. If I paid the whole loan off in a year, I'd be in the negative after interest.
For what it's worth, I did quit; partially because the pay was so low for the 55 hours of week they expected developers to put in.
I know this is only anecdotal, but shit does indeed happen.
After Taxes (federal) Taxes (state) and Rent (insane) more then half of that 100k you reference is gone. Without a gold spoon it's not as easy as you make it seem. Food for thought, I had more disposable income making 65k/Year in Florida then I do making Far more in the Bay Area. I'm not saying that there are not benefits to living here but it's not a golden ticket. Also, clearly you don't have a family to support.
I'm not quite sure you know what the "prototypical HNer" is I live in the Bay Area, I know a lot of people who also spend a lot of time on HN, if I were to make a guess my sample size is larger then yours and I think your assumptions are off but I'll leave it at that.