> they want to be able to choose non-unique ones rather than end up with user53267 or something inane.

Disagreed. I'm 39. I've known hundreds of people (HS, college, etc) and many close friends who willingly made email accounts like "brijacks85" (their birth year) or "sammichelson212" even when their actual names were still fully available on yahoo/gmail/hotmail, etc. I used to regularly create email accounts for these people using just their names and then ask "why didn't you just check your own name first?" and they'd usually just shrug with total indifference and never use the account I made for them.