I think part of that problem stems from government regulation. Why? Because people have come to rely on the government to do their thinking for them, to their own detriment, of course. The general consensus, I suspect, is that housing codes ensure a quality home. That, of course, is not true. While codes have created a minimum level of quality in many areas, they cannot substitute for the knowledgable buyer. Plus, builders don't always adhere strictly to the code.
Let's see how many century homes are around 8 or 9 decades from now.
BINGO!
Housing codes mostly address other issues. And, depending on the climate and the code, they often make the situation worse.
Bingo! Building codes which were designed to describe the minimum standards, have now become the maximum standards. Mandatory codes always have this effect.
And the homebuying public, relieved by the government of the tedium of actualy having to learn to tell quality construction from shoddy, thinks that they are safe.