"Most of the people who go to church can't kneel anymore."
If you wanted something more refined than a national view, YOU should have been more clear.  Where do you get the idea that the presence of kneelers represents a "demand"?  If you can't kneel, there is no requirement that you figure out a way to do so; if you won't kneel, you aren't participating in the Roman Rite fully.  The priest has no right to remove kneelers...plain and simple.