it kinda make sense, why existing population of SF tries to oppose any new building, but I still can't understand why bigger companies need to be there physical

it kinda make sense, why existing population of SF tries to oppose any new building, but I still can't understand why bigger companies need to be there physically except may be top managerial stuff? It still make sense to start startup there, since this city filled with like minded people, but for bigger companies - why pursue it? Me and quite a few of my (married and with children) friends refuse even considering moving to SF exactly for this reason - too inadequate housing situation.