Is it really necessary to own a home if your mortgage is going to be 20 years long? I get that renting is like throwing money in a hole, but people are so much more nomadic these days. What's the big deal in moving once every 10 years once rent gets unbearable?
Rent gets unbearable way faster than every 10 years. My first place in the Bay Area had rent jump from $1800 (uncomfortable but doable), to $2300 per month. This was after just one year of being there, and since then I've noticed that 4 years later rents in that neighborhood are now at $3300 a month for a one bedroom.
OTOH, I lived in Belmont CA on $2000 rent for a whole house blocks from caltrain for over 3 years, no adjustments.