What exactly disgust you so much about /qst/? Honestly, I don´t see that big of a difference with /tg/. Is because it puts trips on people and thus eliminate anonimity?

Everything! But one of the biggest reasons is that the limited life span of the threads forces you, the author, to think on your feet and write as fast as you can (even if I'm horribly slow about it the entire time). The fact that they die after page 10, a hard death, means that you can set up cliffhangers and scenes when the thread itself dies, so it helps keep you going for the next one. But that's just one part of it, and really, /qst/ was made in bad faith, which also sours the entire thing. I'm not saying it's impossible to run a quest there, but it's definitely harder than doing it originally in /tg/.
The nazimods killed quests. That's it.