It was useful because it kept a log of all of the activity you had completed. This was especially useful if you were halfway through a quest, didn't continue it for a long time, and needed a reminder of what the quest was about and what you needed to do next.
What is really annoying about the Skyrim system is that miscellaneous quests have absolutely no context behind them in our current quests menu. "Fetch iron sword" is not a particularly helpful quest log. The previous system of a quest journal would have information needed to remind us of our objectives.
Does anyone else want this feature to return? Discuss!

