I don't agree with that reasoning at all. Some games don't have quest trackers at all, and people still are able to follow their quests in their journal. Just because they aren't on the screen in their face all the time doesn't make them unable to follow. I can't remember what reasoning SE gave about removing it, during the Beta. I think it was something along the lines of they didn't think people were making use of it so they took it out.
The issue is when you change classes, your quest tracker is full of quests that are no longer relevant or even possible for you to do. I'm running around town as a level 25 Weaver and my quest tracker is telling me to go save some random dudes from a bunch of angry animals (level 15 Conjurer class quest). Or as a level 40 Paladin I'm being told I need to go to Quarrymill and make 3 cotton coifs of gathering.
It was very nice during the Beta to choose which quests you felt were priority and deserved your immediate attention. When the Phase 4/Open Beta update came out and that option was removed, it was kind of a shocking moment. A step back in the UI that I thought would be remedied quickly. Then the release came and it wasn't put back, and now 2.1 came and it wasn't put back...
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Can't sleep, clown will eat me.