Get off your high-sawhorse, gellflex. First, as a 3-D printed object it may very well be that someone who rides a wheelchair finds it easier to print something like this at home than go get lumber, pull out the power tools, and fashion something like this out of wood. Second, as a 3-D design, it's open to be tinkered with, so someone might design the next one with different treads, change the angle, eliminate uneeded material to make it lighter, stackable, more compact, wider to accommodate different wheels, etc. All of which makes the product refinement something that can be done by the community it serves, which is far better than having it made for them by someone who distinguishes himself from those pitiable "self-styled makers."
It's amazing to me that some people these days still just don't get some fundamentals of what being a "maker" is about. It's not always about doing it more efficiently, more cheaply, or faster. It's about building something for yourself that meets your needs, learning how to do it, and realizing that not everything that gets made in the world has to be made in China or designed by people who "make stuff for a living". Sorry if the future doesn't include you.