Many do. The vast majority of the parents of the 100,000 or so children in the city are “normal”.
Fewer and fewer every year, but even so.
The impediments to more people staying and raising children are indeed due mainly to the obsessions and failures of liberal politics, but are not really the ones that seem significant to outsiders.
And the majority of all voters vote to keep liberal politicians in power. I'm not throwing stones (I live in Illinois) or casting aspersions on all the people of S.F. but like Illinois, S.F. liberal politicians are elected by the majority.
Our perverts and other liberals are generally confined to one huge city.