Because the overwhelming number of people are in the "no urgent needs" category as they age, they largely don't identify with any perceived issues with their homes. They either don't have any major issues (or none at all) negotiating stairways or narrow hallways and doorways, or using hard to grasp cabinet and door hardware, or they just don't want to focus on the change such improvements might mean because that would mean admitting that age is catching up with them.
In a few cases, accessibility home modifications might already have been made. We will see this more and more as we (aging-in-place providers) get involved in the marketplace, but we are in the early stages of gaining consumer acceptance and being able to offer and implement such improvements.
Back to the assertion that so many homes could benefit from accessibility improvements. This is notwithstanding those where the occupants have mobility issues or limitations that necessitate a modification - even if non has been undertaken as yet and some form of coping or adaptation is being done as a work-around for now.
The reason that so many homes can benefit from accessibility improvements is that they generally were not designed to accommodate the range of mobility issues and aids that we see today. When people did visit homes built in the 1940s, 50s, 60s, or other eras, they generally knew if those homes were going to be accessible to them. People used canes, crutches, or wheelchairs, and were typically familiar with home friendly homes would be to them before they ever arrived. The walker - so prevalent today didn't really come into existence as we know it until in 70s. Thus, homes built prior to that could not have foreseen the use of walkers and been designed to accommodate them.
Older homes were built with smaller doorways than what we recommend being used today. In fact, many home built today still aren't using 36" (3 foot) doorways. Seeing this is an older home that hasn't been modified is rare.
Many neighborhoods were developed with narrow walkways leading up to the home and a series of three steps or more - often significantly more, and sometimes in more than one place. Homes were not designed with the idea of an approach area where people waiting to gain access into a home could stand under cover and to the side of the door - where they would not be hit by the door when it opened outward toward them.
Inside the home, narrow hallways and small entry foyers made interior movement more challenging.
There are more areas that can called out for treatment, but the general idea is that homes traditionally have been built without allowing for people - regardless of their physical size or ability - to enter them easily and then once inside to be able to move about freely. This is why there is such a potential for us to make a difference.