As more and more content get moved from a fixed random drop kind to a "daily quest" kind the number of active quests that you need to take, even after level 50 and nominally not having anymore to quest for leveling, is growing at every patch.
Already 26 are feeling too few, next patch should introduce a wealth of new dailes, weekly, guild quests taken by individuals, crafting quests and so on, it would be really usefull if one could take more quests at a time over the current limitation.