I think he means that when you're tweaking on the "old meth," you'd be more likely to go outside and interact with people (many times, with hostility and aggression), while the "new meth" is more likely to make you want to stay inside, and withdraw from society.
What's cheaper than a tent? 1/2 or 1/3rd of a tent. That's enough if shelter is the only issue. If there is a need for the poorest to have solitude, there's going to be a proliferation in the number of tents.
I mean, given the choice of two explanatory models:
1.) Even in cases of extreme poverty, people will put in significant effort and sacrifice to secure some degree of privacy, because it's a basic human desire (a desire I've seen in nearly every person I've ever met.)
2.) ULTRA-METH PSYCHOSIS
I'm strongly inclined to favor 1 over 2 until I see some very, very compelling evidence otherwise.
1.) Even in cases of extreme poverty, people will put in significant effort and sacrifice to secure some degree of privacy, because it's a basic human desire
And yet, if you look at our actual history, the levels of privacy available to average and poor people were far, far less. In the middle ages, entire families shared the same bed, if they had a bed, or otherwise slept all huddled together. Even complete strangers in inns and other public accommodation would sleep huddled together at times.
Not to say that there was zero privacy. However, there was far less. Much of this was probably motivated by availability/economics.
Many modern claims of "basic human desire" turn out to be a "Flinstones" view of history. Many things are constant across time and cultures. However, there are also some factors which are vastly different.
2.) ULTRA-METH PSYCHOSIS
That's kind of straw-mann-ish there. No one is saying everyone homeless is in ultra-meth psychosis. But the large numbers of people so affected in varying degrees are going to skew the statistics of how many take the extra effort and expense to have their own tent.
