That is a very good point.  I was reading one article about the new McMansions, where a contractor argued that there's no point in building to last.  He said the clientele they are aiming for normally buy a new house every 5-7 years.  Ten at the most.  Simply because fashions change, and no wants a house that's out of style.  Why build to last for decades, when the customer is only going to be there a few years?
They do not even ask for quality to get a high second hand value on their house? Building after the fashion, I would rather build in a way that reflects who I am. I am toying with the idea to build a house if I get the career I hope for. Something practical and reasonably sized that can be usefull for generations and I dont even have kids. (Yet, who knows? )
Whith a gable suitable for building an extension if there is need for more rooms in the future.
They figure when the house is resold, the new owner will want to renovate it, not live in it as is.