There is no legit reason for buying a passport.
There is no legit reason for buying an account.
Where's the problem?
These analogies aren't really relevant and are a bit extreme in comparison, but there would be some valid reasons (though rare) to buy a passport but maybe you would disagree. You could buy a passport to evade the law if you've been unjustly or falsely accused of something (I'm thinking Edward Snowden here). Maybe one day the gov will come after bitcoin users for whatever unjust reasons and maybe some people would have no qualms in buying one if they knew they wouldn't get a fair trial.
By "legit," i mean "without intent to deceive." Sometimes deception is warranted, but that's not the point here--the point is deception is the goal.
As for legit reasons to buy an account 99% of people buy them for signature campaigns. It's not really comparable to selling your identity. It's just a forum handle.
As far as this forum is concerned, an account is your identity, just like a passport identifies you IRL. I used the passport as an analogy, never suggesting that a forum account
is a passport. Analogies are just ...analogous. Don't you agree that a passport is more analogous to a forum account than a 60" plasma TV? If yes, that's all I set out to say (see my first post), and we agree with each other
As far as buying accounts for sig campaigns? I was going under a naive assumption that people posted because they had something to say, and not to earn some change. If those paying for sig campaigns knowingly support this sort of thing, some of the credit for bitcointalk's shittening, undoubtedly, goes to them.
Most of the people who sell accounts are just your faceless average Joes who nobody would even notice if they disappeared or their account was sold. Disallowing the sale of them would just push the activity offsite and underground and that is one of the main reasons they're permitted to be sold in the first place as it's largely unenforceable.
If sold accounts wore avatars clearly stating
"I bought this account to spam the forum with ads in my sig," I wouldn't mind half as much. I'm also sure those accounts would not net their sellers quite as much coin.
I also wouldn't mind it if buying/selling of accounts was not sanctioned by this forum. Just like I''d be sad if rape became sanctioned in US, "because only a small percentage of rapists are brought to to justice anyhow, so we'll just let them rape right in the middle of the town square--otherwise they'd just do their raping in dark alleys."