Adding someone to the distrust list is not a "use of the trust system against someone". It's a matter of personal opinion about someone's views.
What about the other points? Like leaving a negative feedback of removing a positive feedback for political reasons?
Everything is a personal opinion of someone's view, if someone gives you a negative feedback saying "you are a scammer" it is their personal opinion too, which they are entitled to, are you not going to demand the removal of that tag or the person behind it?
If everything is "personal opinion" then there is no need for a default trust list, we should let everyone express thier personal opinion without any community consensus.