Massive housing developments in Mission Bay continue to sprout up, trying to keep up with overwhelming demand in a city bound on three sides by water. We can't sprawl, as other cities have, so we redevelop and go denser.
For those of us who like New York City, this isn't a bad thing - this is nowhere near the density of Manhattan! - but accommodates more people and does allow us to grow. It's good when a city has variety - NYC has brownstones AND highrises! We have a collection of housing styles going back to the Mission era, with a great stock of Victorians AND very new/contemporary styles. I enjoy the variety in texture.