The trust system is something that needs a lot of improvement here. From what I understand, if a member gets a negative trust here, his profile become useless. He gets no chance to rectify his mistakes.
In case of merits, there is no negative action taken and it is good for all. If you do not get merits initially, it does no harm to your profile. You can always improve our posts and then gets merits to rank up. We cannot however generalize the whole system based on few incidents.