One look at the DefaultTrust network, especially at depth 2 reveals what a sham the whole system is. Many of those in tier 2 use the system as a weapon and give negative feedback that has nothing to do with trust or no trust. Heck, a fair portion of those in or previously in tier 1 have done the same thing. Tell me, how are those people any more trustworthy than a random person on the internet? The answer is, they aren't. They should not be trusted by default.
I disagree. People who engage in this kind of practice tend to get removed from the default trust network pretty quickly. There are plenty of examples of people getting removed quickly after engaging in this kind of activity. There are also a lot of examples of people claiming abuse when there is really none that results in people not being removed - these people are almost universally scammers. And then there's my example, where someone aggressively libeled me, I defended myself the only way I could afford to (can't afford a lawyer), I got removed from default trust T2 x2 as if I was one of those "almost universally scammers", and the aggressor still remains at T2 off BadBear's T1, 6 months later, an eternity in internet time.
For justice why should libelers' ratings be endorsed by default trust
Someone that, over time, slanders others, will eventually make their way onto people's ignore list. If you really are as honest as others believe you to be (and as I believe you to be) (and as you present yourself to be) then no one will take such slander without proof.