The entire DT system actively fights against plagiarism and ban evaders, including being severely banned, permanently. And scammers ... they are not even moderated.
Yeah, I hear you there. DT members do try to combat scammers, too, but bitcointalk is unique in that scamming is allowed. I've never seen another discussion forum where that's the case.
And as far as the reasons for this, you'll hear all sorts of explanations that I think are excuses being made on behalf of Theymos.
Any scamming incident is bound to have a two-sided story and it's not so clear cut.
That's an excuse IMO. There are very clear-cut cases of scamming, and yet the scammers never get banned. True, their trust page ends up looking like it was splattered in arterial blood, but the end result is that their account is still active and they can pull off more scams if potential victims don't (or can't) see the red trust.
I never understood why scammers aren't banned, but it's a fact I've come to accept in my time as a member here. I always keep in mind that this isn't my forum and I don't run it. That isn't to say you shouldn't try to suggest improvements, and I applaud OP for writing his post....but the sad fact is that I'm fairly certain nothing is going to change.