So seems like they have a process then, why not have it available to consumers as well (even for a price perhaps)? Is it that a personal user's $700 device just not important enough?
I'm not sure I can elaborate on why it isn't available for regular customers. Education and enterprise customers have to purchase the devices under the name of the company, and the process is in place because plenty of businesses and schools issue phones, then the person quits or gets fired, and that person cannot or will not unlock the device. So Apple has to provide them some way to remove the iCloud account from the device so that it can be reused.
Now for a regular consumer, just because you have the receipt, doesn't mean that you are the owner anymore. I don't have a problem with this process not being available to the regular consumer. Don't forget your Apple ID, and there won't be an issue.