Why is it so hard to find an economical home that's designed in an elderly-friendly manner?

New houses are all about form - function is way down the list. I'm convinced that new homes are designed by people who never cleaned a day in their life. My plan is to buy a piece of land (not sure where yet) and put a prefabricated AD/mobility home on it. I'm hoping that by then, geothermal will be more mainstream and there will be a real health care system in this country, regardless of whether I choose to live in a rural or urban setting.

My sentiments exactly ibzook. I live in upstate NY. We are in our 70's and looking for a simple ranch style home - one story so we can remain independent with something manageable. We have a large colonial and its too much for us. I can't keep carrying the laundry down to the basement!
But, we are not old enough to want to give up 80% of our possessions to move to independent living.
Senior communities are great but the homes they offer have no basement, no storage building for hubbies tools and hobbies, and usually garages too small for his pickup truck (used to pull camper). Also, most IL's don't provide a lot or place to park a boat, camper because you can't put it in the driveway.
Every newer home is a mini-mansion with open floor plan and 10 foot ceilings, lots of stairs and not senior friendly (or appealing). We would like to stay in a "residential neighborhood setting" but builders don't want to put up small homes because they "don't fit" with their mini mansions with peaks and gables. None are building "starter homes or senior homes". We considered buying land and building but it will cost us more than staying where we are and its hard to find single lots that aren't on a main road of some sort .
We have found plenty of "older" single story homes in older developments - all needing a LOT of remodeling and money to update them.
I wish we could go back to the "good old days" when a nice 3 bedroom, 2 bath ranch (of about 1500-1800 sq ft) with a basement and garage was the norm, not the rarity. Why won't IL housing provide more choices?