Interestingly, a while ago I had an application where JavaScript was added later on in the game. The result was that we could split into two apps: a rich fast glitzy one and a basic one suitable for mobile devices.
That's one of the best arguments for accessibility (and the associated host of issues like semantic HTML and Javascript). Sometimes things you do in the name of accessibility will bring other benefits.
I read an interesting analogy in an article (which I have since lost and so cannot give credit) about accessibility: Oxo, the kitchen tools company, started by designing tools for people with arthritis. Having designed tools with nice soft rubber grips and large handles, they discovered that non-arthritic people really liked the tools as well, and now Oxo is sold at your local Target (and they are probably raking in cash).
I read an interesting analogy in an article (which I have since lost and so cannot give credit) about accessibility: Oxo, the kitchen tools company, started by designing tools for people with arthritis. Having designed tools with nice soft rubber grips and large handles, they discovered that non-arthritic people really liked the tools as well, and now Oxo is sold at your local Target (and they are probably raking in cash).