Density is an imperative for Los Angeles, and big sprawl-y cities generally. And we're building density! DTLA is getting more residential, train stops are getting surrounded by everything from 5+1s to superblocks, Santa Monica is getting taller, ...

That global imperative does not translate into a local demand that every SFH (and in particular, these SFHs) be replaced with denser housing. As you realize in your comment, the damaged areas aren't exactly well-positioned to support substantially denser housing.