Bewitched woods brought the party problem back in its full harshness with people dropping a beacon with "targeting rare items" and after 5 minutes going straight for map's boss without saying a word and/or abandoning the quest/disbanding the party dragging everyone out.
Leaving the wasted boosts time question aside, the 14* drops are already low, taking the risk of being dragged out during a fight with a boss is frustrating, specially when the generated map's shape is a decent one.
Add to that the fact that some 14* are being sold for outrageous prices (considering that soon enough they'll probably be in zieg exchange with hero's crests already dropping) and buying them is not an option for many, given what happened with nemesis/raven, you should understand the reason why joining a party for a 40% triboost is not worth the hassle.