The notion of "a fundamental right to housing" isn't about "where cool restaurants are." It's a starting point and a framework for how you solve the problem. There are complications that we definitely have to figure out (including where etc) but the conversation always comes back to the strawman of "well it's just not fair to buyers, and those people need to make better economic decisions."
If a person is paying $1000 a month, and sees a 2% increase every year and can afford it, but then can't afford a 100% increase in one year, are you saying they made bad economic decisions? OR that they should have anticipated the housing market to shift so drastically?
Of course not, because, as you said, it is absurd to not consider ones actual economic status.
Wrt to the newly homeless who have been evicted - i think it is convenient to chalk this up to market economics, but the truth is that zoning, housing, and rental laws have created an environment where you are seeing mass displacement of people. You may say "well that's the market" but you might feel different if it was you and yours. It also trivializes the value those people bring to their communities, and the lag effect in economic production their displacement will invariably produce. Longer commutes = less productivity (http://www.cityam.com/265145/heres-just-much-impact-long-com...).
I don't disagree that you need to consider economic status, but in that vein, it's worth considering that housing laws help us define the values we want in a community and sometimes those are not always economic.
At the end of the day, there is pretty conclusive evidence that building more affordable housing is good for cities.