If a user ignores the DT-WEIGHT and does as he likes then he obviously doesn't deserves it and on the other hand if a user knowingly does this then he is abusing it and should be removed.
So because someone's feedback makes a difference to the majority of users, they shouldn't leave the feedbacks that they did previously (which more than likely got them onto the DT list in the first place)? That logic seems a bit strange to me.
Regardless, the main difference (for me) between selling a BitcoinTalk account and a LocalBitcoins account is the risk that comes with selling one and not the other. Whilst BitcoinTalk doesn't condone selling accounts, they wouldn't terminate the account for it being sold. On the other hand, selling a LocalBitcoins account is against the ToS of the site and can result in the account being terminated and the user being left without an account or the Bitcoin they paid for it.
Unless this risk is explicitly presented during the sale (which in this case it is not), I consider a negative trust to be worthy as the OP is selling a product with an unmentioned risk, which could result in them scamming (intentional or not).
PS. You also do not need to create two threads for this. By posting repeatedly with insults simply makes you look like a child who is throwing a tantrum because they cannot get their own way.