From the broad, shallow social perspective, I do think it makes a whole lot more sense to focus a lot of money on increasing the ability of the disabled to participate in the physical world unassisted (as through something like this, R&D $$ intensive or no,) than it does to spend an equivalent amount of resources on the converse - trying to make the phyiscial world more accessible to the disabled (via curb cuts, handicapped spaces, extra-wide bathrooms, etc.) I'm confident that the several billion $US / year focused on the latter could make some huge strides in the former at better cost...