I think his point is that standards are inherently arbitrary and inflexible and that these specific standards are only beneficial to a "small group". My point is that these standards aren't arbitrary, but well-reasoned, and that they are broadly beneficial (see my post elsewhere for some more examples).

Some standards are enforced by law - fire codes for instance, or food handling standards. Do accessibility standards merit similar treatment? I'd argue that most people now need to use the Internet for basic functions in their lives. For instance, you can't even get a job at a chain grocery store around here without filling out an online application. Given that, there's a strong social interest in making sure that everyone has access. That interest has to be balanced against other interests - costs to businesses for instance. I'm not necessarily suggesting that we should treat WCAG the same way we would treat a fire code (which a government agency enforces) or as we treat ADA building compliance (where customers can sue to force compliance), but I do think that a debate on this issue should look at what these standards actually do, and try to balance the interests. I don't think the parent is doing that.