Considering the number of places/events that seem to give no thought to how people with disabilities are going to manage, it's nice to know the Royal Family and staff appear to go out of their way to ensure those with disabilities are accommodated.
As to dress codes, would you go to a mosque in short sleeves or to a Vatican audience in hotpants and a crop top? A posh restaurant in ripped jeans and a dirty t-shirt?
You're being ridiculously disingenuous, and making yourself look a little silly in the process.