Why, they're investments. Of course you want prices to go up!
You're sinking a huge quantity of money - presumably, above that of an equivalent rental unit in your region - and by golly, you need returns on that or else you're just fritting it all away.
It's all compounded by the fact that housing is the only major asset investment that the vast majority of people ever engage in.
They're only an investment if you buy more housing than you need. After all, you need housing, so when you sell that home at increased value, you will need to use that revenue to buy new housing which has also risen in cost.
In short, only if you can sell your home and buy a cheaper home can it be considered an investment. Otherwise it's just non-liquid capital.
In theory, if you buy enough housing to fit a few kids then you'll have more housing than you need by the time you're looking at retirement, so you can cash out your 'investment'.
Of course, in reality this never seems to actually happen.
Lots of people are doing this / have done exactly this.
My parents and many of their generational peers (boomers +/- 10 years) did the large house thing in the 1960s-1980s in order to raise the kids, then sold their large house and moved to a smaller house or condo as the kids moved out in the 1990s-2000s.
You're sinking a huge quantity of money - presumably, above that of an equivalent rental unit in your region - and by golly, you need returns on that or else you're just fritting it all away.
It's all compounded by the fact that housing is the only major asset investment that the vast majority of people ever engage in.