Ever see a movie or read a booK where someone does something stupid and gets the whole group in trouble?
If you come into a system like this one with a D20/d&d mindset, there is little point, and you will never understand it or have fun with it. THREAT is a more modrrn/indie style system that models/drives the fiction/story with it's mechanics, it is not tryjng be a simulation of task resolution with mechanical balance at the forefront. It creates opportunity for a good GM to make the story more interesting. Its not there as a tool for a sadistic dm to punish people.
See DungeonWorld for a great example of a system thats been around for awhile where the mechanics drive the story ever forward, instead of being a simple pass/fail mechanic.
Here's a good, hard example showing why I don't think the mechanic is a good one, but also asking why you do think it is a good one. I posted this on another forum, but it works here, too.
The Situation
You are in a team that includes Conan, Valeria, Subotai, and Akiro, and you are infiltrating Thulsa Doom's Mountain using the caves near the gorge towards the north face. Everybody is being cautious, not taking any risks, except for Conan. Conan hates Thulsa Doom. And, he's in there swinging hard and dispatching enemies with extreme prejudice.
Because the one guy is fighting hard--he's just taking risks when he fights. It doesn't mean that Conan is being loud and attracting attention. He's grim and quiet. But, when he swings, he's ruthless and savage (in game terms, spending extra dice to fight that way, and increasing the Threat Pool when he fails).
Originally, the GM had two guards watching that back cave entrance, but now, since the Threat Pool is higher, the GM can spend those points to increase the number of guards that the players have to fight.
Why is that a good rule?
The characters really did nothing to attract more attention--yet, because of the savage nature of one, there are more enemies to fight.
How does it even make sense?