SpaceHelm I don't agree with the removal of take all option the OP suggested cause it is quite useful. But to answer your question, it can be a hassle having so many quests if you are farming some specific place/mobs like the 300 D1 mobs for example and you need to check whether you have enough kills through the on screen quest display. Too many quests also can prevent certain other quests from registering thus you need to delete some of them.
Maybe the OP just doesn't like his quest registry to be too cluttered. IDK.