Why do so many Americans put up with cheap, crappily-built houses – even when those houses are "McMansions?"

It’s kind of amazing. Americans are willing to buy housing made from extremely cheap materials that will fall apart after only a couple decades, or at least require expensive repairs. Why?

When I was looking around to buy a house, the real estate agents kept trying to steer me to these crappy wood-framed garbage houses that looked the same as every house nearby, like they were all part of the same cheap development. I demanded to know where the "real" houses with brick architecture and sturdy roofing were located, and they tried to pretend like such houses didn’t exist.

This was false; I eventually found a house built back in 1925 with brick walls, a real wood stove, a real basement and cellar, and so on. No inch-deep fake stone cladding – this was the real stuff. After having it renovated and wired for high-speed internet and putting in solar panels and a ground heat pump, the house was ready to go, and at the same price as a cheapo McMansion in the distant suburbs.
This is an EXTREMELY political question. Politics allowed this to happen. Local zoning boards, all the way up to the federal government giving tax breaks to builders and new housing developments.

My question is, why, politically and socially, do Americans tolerate this? A lot of this recent housing stock is ABYSMAL in quality.