Disagree. Plenty of middle class people who struggle with housing costs. I'm one of them. If you know the state of Australia's housing market this is obvious.

What definition of "middle class" are you using that includes "can't pay the rent/mortgage"?

Note that losses from rental properties don't count as housing costs, that's just poor business return.

We were talking about people delaying/avoiding children for financial reasons.

That doesn't imply "can't pay" necessarily, but when rent/mortgage payments are high, that leaves less spare cash floating around for the additional/unexpected expenses, a scary prospect.

Even those on comfortable incomes can find them unexpectedly disappear.

I think taneq is implying that while you might beleive you're middle class, the fact of struggling with rent, by some definition of middle class, makes you not middle class.