From what I understand Bay area is survivable for those who already have family there or who have a 200k+ tech job.
Otherwise it has ludicrous prices that make Hong Kong, Singapore and Vancouver look cheap.
You're absolutely right.
If your salary is $140,000 a year in San Francisco (this is well above the median salary in San Francisco), you'll end up with around $95,000 after taxes. A decent studio apartment in San Francisco costs at least $3500 a month, or $42,000 a year. If you don't feel like paying this much money, you'll have to live with multiple roommates or deal with a long (probably more than 2 hours per day) commute. Now you're left with $53,000. If you're frugal, you'll spend around $20 a day on food or $7300 a year. If you're lucky, you'll spend around $3000 a year on utilities and gasoline in San Francisco. I'll assume you already have a car. Now you're left with $42,700. Not bad.
If you're able to keep your job for the next 7 years, you'll have enough money for the down payment for a $1.5 million house in the Bay Area. A house worth less than that in the Bay Area is probably not suitable for raising a family. 7 years without eating out a single time, going on a single trip, or spending a single dollar to entertain yourself, and you can finally pay the down payment on your dream home (which probably isn't all that great). Now you can look forward to paying $10,000 a month for the next 30 years to pay off your mortgage.
If you don't want to spend your next 37 years like this, I guess you're a loser (according to another user).