Seriously. Comments like that are the reason I try to frequent HN less often. I grew up in the mission in SF, but that was when it was still a 'ghetto' that nobody wanted to set foot in (I still have a lot of friends that are paranoid about it), and as you might assume from that, my family wasn't ever that financially well off either. So seeing things like this just makes me cringe at how disconnected and insensitive this newer wave of (for the lack of a better term) 'more fortunate' people are.
Being able to simultaneously look at the absurd rent prices in SF, and then interpret the homelessness problem as a 'choice' is some serious obliviousness, if not an all-out exercise in orwellian double-think. I know it's a bit of a popular 'thing' amongst a certain subculture in the Haight (hell some of my friends have done that), but that's been around for ages, and I'd hardly call that culture a majority...
The original article pretty much got it right: people here like living in bubbles.