Most people (Not just Americans, but especially them) are obsessed with the value of the home they own.
This is largely the result of the strong "you must own your own home" thinking [1], coupled with the pervasive argument that your home is an "investment".
It would be helpful if people understood that most buildings require (expensive) maintenence. Most buildings depreciate with age (materials, style, wear and tear etc) and so the idea of "property prices always go up" is either a myth, or based on increasing scarcity.
Naturally though since the investment idea is pervasive, scarcity is the obvious consequence. And by extension anything that affects value, in a downward direction, is by default a negative.
[1] the root idea is that people who own will be more stable, and less likely to indulge in anti-social behavior, like say revolution, since they have skin in the game, and "too much to loose". Prevent rebellion against land-owners by making the rabble into land-owners.
Which is solid thinking, and has resulted in very stable, socially-responsible populations. Who, it turns out, care mostly about property value to the exclusion of everything else.