Lauda will sometimes remove negative ratings that result in the other person stopping being critical of him. It is not always people that can affect his trust score, however it is probably people that are making good points. It is fairly clearly a quid pro quo.
Why is this a problem?
~BCX~
This is essentially using his position in the Default Trust network to prevent others from criticizing him. It allows Lauda to act questionably and not be questioned about said shady/dishonest practices.
Why is this a problem?
~BCX~
Because in QS land only certain people are allowed to resolve trust issues through communication - as they are meant to be.
Often times the criticisms about Lauda are unrelated to sent trust. This also prevents an open discussion about Lauda's actions.