In that case, trust is irrelevant for eBay accounts, since, as long as you trust eBay, everything works out.
Bitcointalk accounts aren't backed by a central entity, and the trust you place in them is not a proxy for trust in some central entity.
To be useful, it must be real. If accounts are bought and sold, it is not. It's a charade.
But thanks for taking this thread back on topic.
Trust can be either relevant or irrelevant. It's a guide for you to make your own mind up on. You can disregard the entire system or judge feedback and users on a case by case basis. You can probably buy accounts or memberships to the majority of sites on the internet. I can buy a degree from Harvard or fake passport online. Does that make those institutions a charade too? People can only protect themselves at the end of the day and it's most certainly not the job of the staff or admin's of this forum to do so, nor would it be possible, hence the rules we have here whether people like them or not.