As one who advertises exactly what you're mentioning, it's part of the marketing. Same as displaying combat stats, unique/untradeables, quests, OO etc. Granted it doesn't make the account bulletproof, however it does adds a blanket of security.
In the account selling format it asks for original owner and a registered email. It's going to be seen and mentioned no matter what.
Instead of attacking others business, inform the buyers out there of your stance