Kneelers are simply a traditional western expression of humbleness, not part of the doctrine of faith.  In Oriental countries, kneelers aren't used as it isn't their cultural expression of humbleness. Not sure about other parts of the world.  The point being, the church - both clerical and the faithful - sometimes get confused as to what is actually the faith, and what is merely the expression of it.  The former is unchanging.  The latter is by definition, constantly changing.  Interestingly enough, this is a similar battle Muslims face in the wearing of the hajib, or headscarf.  Some Muslims (and non-Muslims) mistakenly see this as an article of faith, while others see it and use it as simply an expression of their faith.