If you're going to rant, you should at least rant with realistic numbers. A $500k house at 4.5% (which is still historically crazy low) interest is $2.5k / month. That's before the "TI" part of "PITI" which would probably add another $500 or so a month. So... about $3k.
Let's assume another $1k / month for 2 cars, gas, and insurance. Now we're at $4k. (PS: if you want to assume they don't have cars and can use public transportation, then the house costs will likely offset the car savings).
Let's hopefully believe they are putting some money away in a 401K. Another $1k / month, so now we're up to $5k.
About $2k are lost to taxes & health insurance. We've just hit $7k.
That leaves behind $2k / month in spending money. The chances of putting another $900 away every month seems unlikely, regardless of "basic budgeting skills and self control".
The good news is that they actually have that $2k per month in spending money... Most families can't pretend to have even that much.
Could they get a cheaper house and save $1k off of their housing costs to put away? Well, if you use $300k rather than $500k then the same search you used to justify slamming this hypothetical family now returns exactly 30 results for a 3 bedroom house, as opposed to "hundreds".