There are many workarounds for this issue, for example, use a link shortener service like bit.ly etc., to shorten greenaddress' "permanent payment URL" service.
Hence: your short, easy to remember link -> greenaddress url -> bitcoin address.
Or simply use QR Code. No need to deal directly with complex addresses.
Best answer so far on this thread! the long public address is created for a reason such as adding layer for the security, being unique and making hard for scammers to imitate. the idea of converting public address into a digital name is pretty good but the problem is it will be easy to replicate if you choose an easy to remember digital name.