You are right that is not what Bitcoin is about. However Bitcoin is also not about determining who is appropriate who can be trusted. The question if a node will accept a Bitcoin transaction is very black and white while if someone is trustworthy is extremely subjective. There is really no criteria that can determine if someone has scammed in the past and good judgement really needs to be used.
I can say that I was a supporter of the default trust system long before I was a part of the default trust network. I can also say that the default trust system was able to protect me from a number of scams when I was a newer user.
Prior to the default trust system there was the scammer tag system which was even more centralized and was reactive instead of the proactive system that is in place today.
What would you propose using instead of the current system in place currently?
What? Of course bitcoin is about determining who is appropriate to be trusted. That's exactly what it's about. It's about giving the power back to the user to trust those they wish to trust and not be forced to trust those they don't wish to trust. Bitcoin does not say "You will only connect to these trusted nodes unless you configure otherwise." it says "You will connect to everyone and decide who you wish to exclude."
It does not say "You will process only these transactions that you agree with and trust."
It says "You will process all transactions unless you choose to exclude them."
If the default trust system protected you from a number of scams as a newer user, that's on you. I simply don't understand (and I admit that perhaps I am in the minority here) why people can't spot a scam. Or barring being able to spot a scam, why they don't take precautions to prevent being scammed, such as using escrow. If you were naive enough to get scammed here by these amatuer scams, then you have much larger problems. Being protected by little tin gods on a forum is only going to further your vulnerability elsewhere, as you will become reliant on the nanny system to protect you. If what you say is true, Bitcointalk DefaultTrust has done you far more harm than good. But that is a different argument we can have elsewhere if you want.
The prior system was a joke as well... the scammer tag was unevenly applied and was completely arbitrary. The "new" trust system is equally a joke, just a larger one. But let me state it again, since it seems to have been lost. I am not saying we should remove the trust system. I am saying we should remove DefaultTrust as new user enforced trusted entity. It should be removed. Everything else can remain in place and it will function MUCH better for everyone involved.
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.
That is the point I am making. I am not saying get rid of the trust system, I'm not even saying get rid of DefaultTrust. I am saying stop making DefaultTrust enforced by default. Make it "SuggestedTrust" or something similar that a user can add if they so desire, but the trust list should be empty by default - meaning you don't trust anyone.
As a side point, and perhaps I should post this elsewhere... but what the hell. It's easy enough to get a green rating, you just seek out someone in tier 1 or 2 and do a few small trades with them. Bingo, green rating. But that's the rub - you have to trade with those in tier 1 or 2. If you just go about your business on the forum without explicitly seeking out tier 1 or 2 members (or run across them by accident), any ratings you get are irrelevant and meaningless. So again, we are back to the men in the ivory tower deciding who is trustworthy and who isn't. As long as you don't piss off the people in tier 1 and 2, you will remain neutral. If you seek to appease them, they will bestow some green upon you.
What a shitty system.