It really depends what the absolute value of the remaining 50% is. If it's <=$2k/month then yeah, that's pretty bad. If it's $5k/month then you can still live a very nice life and afford many things, in the Bay Area. Don't forget, products bought online still cost the same anywhere in the US (well, almost, there's sales tax involved).
I think people get way too caught up in "oh but I pay <insert large percentage> on housing, that's terrible". It doesn't matter. What matters is how much money you have left after having to pay for rent/mortgage, food, car lease/insurance/registration/gas and utilities. If that amount of money allows you to go to restaurants, go on world trips, buy the latest gadgets/hardware then who cares.
I feel that people complain about this because they imagine some kind of unrealistic scenario "oh, I make $150k/year, imagine how much I would be saving if my rent/mortgage wasn't %50 of my income". Newsflash: rent and mortgages are that high _because_ you (and many others like you) make that amount of money, so pick your poison :) Of course, it's a completely different situation for most people that aren't working as engineers for tech companies in the area...