Perhaps this should be a customizable option for users to set.
It is customizable,
as you very well know.
I generally agree that in order for someone to be excluded from your trust network, there should be a strong consensus that the person should not be in your trust network, so a maximum of net 0 is appropriate for someone to be included (assuming one inclusion). I also don't think that having a limited number of "bad" people in your trust network is not the end of the world, especially if this person is not regularly sending trust ratings.
I'm not talking about my network, I'm talking about Default Trust. You obviously know that the Trust System is customizable, or you wouldn't have customized your own. This wouldn't change anything for those of us who've customized our trust lists, it would only have effect on those who have not customized there's, i.e. newbies and those who've yet to bother.
Oh, you are referring to the default, default settings. I made my argument in the post you cited that the status quo should remain.
The option to customize the number of net inclusions for someone to be included in your trust network is not currently available. Currently, if someone has a net 0 number of inclusions (with at least one inclusion), they will be in your trust network, and the only way around this is to manually exclude them. I was proposing to allow for you to require that at least
x number of inclusions to be required for someone to be in your trust network if they are not explicitly in your trust list.
Here's an example of why I think this is worth discussing; I recently included a member into my trust list who's not very active but has been here for a significant amount of time, and seems to have a good head on his shoulders. He came to my attention when he questioned me about a tag I left for a suspected scammer, suggesting that I may have jumped the gun. His concern was admirable, and showed restraint. I've had the same concerns in other situations. After looking through the reviews he left for others, and reading some of his posts I decided I wanted to see his reviews in my custom trust system.
Since I'm on DT1, now that I've added him he's on DT2. My actions have an affect of the trust lists of the majority of forum users. I don't believe that I alone should have that power. If some other DT1 member feels the same way about said user, then great, I'm not alone.
There is one thing you are leaving out -- the underlying reason why someone has this power is that many people have included the person in their trust list. Those who are on DT1 is (somewhat) random, and does rotate, however the people who are on DT1 are not arbitrary, they have effectively been chosen by the community to have this power.