This used to be Town vs Gown - the conflict between usually rich University students and those who actually lived in say Oxford.

Are well funded techies forcing out old people from their homes? No. Are they crowding out the marginal turnover of housing stock - yes. Will this matter? I don't know enough about SF to say for sure, but a town with a proud history, functioning democracy and plannin laws and plenty of juicy tax income has a problem that lets say Detroits mayor can only dream of