https://en.wikipedia.org/wiki/Barcelona#Population_density
Not manhattan.
Like look at this random spot in barcelona: https://www.google.com/maps/@41.3974472,2.1586211,3a,60y,125...
Not so dense by the standard of Brooklyn, either. Brooklyn is 1.5x denser than Mission.
And that is the average density for all of Brooklyn, Brooklyn being 40x larger than the Mission District.
Citation absolutely needed. Show me source of your numbers. Brooklyn runs the gamut from skyscrapers to single-family houses, but the average construction is 1-3 story apartment buildings, just like the mission.
In any case, even if you're right, it's not a counterargument: how does the western 3/4ths of SF compare to Brooklyn? Why should we be focusing on the Mission, and not, say, Sea Cliff?
Let's try to put a condo building to Jack Dorsey's mansion and see what happens.
https://en.wikipedia.org/wiki/Brooklyn
https://en.wikipedia.org/wiki/Mission_District,_San_Francisc...
> Why should we be focusing on the Mission, and not, say, Sea Cliff?
Why not both?
http://www.city-data.com/neighborhood/Mission-District-San-F...
It's sad, for example, to see so much discussion of the Mission in San Francisco (which is already quite dense, by any standard short of "midtown manhattan"), when the western 3/4ths of SF (much of which consists of wealthier people in suburban-style mansions) is routinely ignored. And though I believe that YIMBY people do want to raise height limits and density everywhere (good, fine), in practice, the debates usually center on re-development in poorer neighborhoods, since it's an easier political lift.