Access Keys Need to Be Customized to Be Useful
In order for access keys to be actually useful to the end Website Designer , the actual keys must be different on every website. Every site has a different purpose, structure and different content.
Not all websites, for example, want a "Donation" page, a "Buy Now" page, a "Complaints" page or a "Products" listing. If access keys are standardized, websites will end up with many access keys that are irrelevant to them.
In fact, the only access key that is relevant to all sites is probably the one that leads to the "Home" page. And I'm sure someone will come along and tell me that there are sites where that aren’t meaningful either.
In other words, standardizing access keys brings no benefit to anyone. Since access keys need to be standardized to be useful (see earlier point), and they cannot be standardized otherwise they will be useless (this point), it seems to me that the entire concept of access keys is not well thought through.
In my opinion, it's far more useful, where accessibility is concerned, to improve the browser keyboard interface, so that a user can easily hop from link to link, form field to form field, locate text within the page, jump from section to section, activate a link, etc.