That's all well and good that you disagree, but SF has 13.4% persons under 18 compared to the national average of 22.6% [0]. There are very few kids / families.
[0] https://www.census.gov/quickfacts/fact/table/sanfranciscocit...
[0] https://www.census.gov/quickfacts/fact/table/sanfranciscocit...
13% of 800,000 is about 100,000. Very few.
My point isn't about in comparison to other cities, it is more, does a smaller rate really mean "few" and how much of a problem is it really. It's not the problem that the most negative naysayers will claim. Note I didn't say something like "affordability poses no problems for families". Because it does. But there is indeed a vibrant community.