Selling your account is not reason to be removed from DT.
How does that make any sense?
If I sold my account I would absolutely expect it to be removed from DefaultTrust.
The new owner should need to build their reputation rather than being allowed to buy someone else's.
I can see that it makes sense not to remove old negative trust when it appears that an account has been sold, because otherwise faking an account sale is an easy way for people to clear their negatives. But allowing positive feedback to stand after an account sale makes no sense as far as I can see.
There have been other known sold accounts that have been allowed to remain on DT
Again with the "those other guys did it so it must be OK for me to do it" argument? That is faulty logic at best.
It is not against any rules to sell your account. If the person sponsoring the sold account still trusts the ratings of that account then there would be no reason to remove them.