The problem with making anything timed in a game is the fail state may result simply from a distraction, however necessary or unnecessary. Whether it be a cat jumping on your keyboard, or a sick daughter.
I also hate the timed quests of WoW -- like "get this item to somebody in Stormwind in 30 minutes or less". Especially because a lot of the delay in finishing the quest came from things you couldn't control, like the flight speed of gryphons. I notice they don't do those much anymore, although since MoP they have been doing "timer" type quests where you need to successfully defend somebody from attackers for a fixed period of time.
Personally, my "meta" view is that time isn't passing (in the game) when you're not (as the player) doing anything. That is, although from the player's point of view, it may have taken you 15 minutes to respond, in fact, no one noticed your character just sitting there for 15 minutes, they perceived the response as instantaneous.
You know I don't like action-rpg mechanics and that strikes me as another; while yes, I understand sometimes you need to respond to things quickly IRL, the game shouldn't be testing the player's ability to react quickly to dialogue. Why? See first paragraph. Players shouldn't fail because their cat is now on the keyboard.