I think that what contributes to this view is that new construction always seems to be at the high end of the market. This makes sense, it doesn't cost the builder a lot more to build a $500k house than to build a $250k house, and building two $250k houses will take twice the time and close to twice the costs. So builders/developers are going to build what is most profitable, which is the most expensive houses that t…
New construction is kept expensive mostly through complex rules that often exist to protect the interests of those doing the construction work, those owning existing houses and property, etc. It's a form of artificial scarcity. This scarcity is crucial to justifying real estate prices, propping up mortgages and the banks that provide them, etc. There's no technical reason why building some shelter that keeps the rain…
Crime and social class segregation is another aspect. Who lives in a neighborhood matters as much as the physical assets. Bans on MDUs (multiple dwelling units), permanently parked RVs, and manufactured homes serve as a barrier to entry. It’s not explicitly stated but the effect is the same as saying “If you can’t afford a $410,000 house we don’t want you as a neighbor.”