>It just these people are in, what, the 0.000001% or something?
Exactly. It's not comfortable, it's not safe and cozy, it's not that cheap that homeless people would buy the BahnCard 100 that you couldn't find some form of cohabitation for a similar price.
And then there's the constant strikes as of now, so you might go days without shelter or need to pay for hotels which adds up quickly.
I'd say this is a rounding error