Absolutely not.
why?
I like the option to go back, log into my old accounts, and just goof off for a couple of days for nostalgia.
It's probably illegal. Whether someone is using it or not its still their purchased property.
Reputation matters. And that shouldn't stop when a person stops playing the game. If their account is sold to someone who's a complete tool then anyone who knew the original owner could be misled into believing their friend as taking a dramatic turn for the worse.
Probably another half dozen reasons easily, if I thought the topic was worth the time it'd take to type them out.