most people i see use it for sig-campaigns or promoting altcoins (thats what my old hero account did) ...
Ah, so you have a pony in this race. Gotcha.
Nah, bro. Selling aged accounts to be turned into spambots is plain wrong. No excuse for that, no explanation necessary. It's not even crime, just petty vandalism.
The only way for it to be less wrong is if, instead of advertising some ponzi in clashing colors abhorrent to nature, the sig space openly stated:
I bought this account from onemorexmr so I can make a few bucks at your expense!
I bought several of these, so when you see one-line posts with
eye-raping blue/orange BB code
telling you to earn 500% a day, remember not to reply to me--I don't speak any English anyhow. Just thank onemorexmr, he's probably aging moar to make this place un-fucking-readable.
Here's his user profile: https://bitcointalk.org/index.php?action=profile;u=464040
Remember to thank him now, don't forget!