Many players are getting used to the new dailies in Guild Wars, especially the PvP-based daily. With the two PvE-based dailies, they cannot go on insta-farm mode because of the need to have the mission or explorable area unlocked. Players cannot just create new characters and attack the mission or boss. The PvP-based daily allows for insta-farming because players can create new PvP characters in order to redo the quest as many times as they want.
Now the balance lies in the fact that with PvE-based quests, players can complete the daily Zaishen Challenge by using heroes and henchmen and normally PvP-based quests require grouping up with active players, which would feasibly slow down the farming of the PvP-based daily. The outlier is Hero Battles, which pits one player and three AI-controlled Heroes against another player and three more Heroes, because the only other player needed is the competition. In a game that touts skill over time played as a banner (and in a perfect world) this would not be a problem… except when devs create “long term” goals that require players to do a lot of dailies, player-driven efficiency kicks in. (Whether you want to call repeating the varied and different Zaishen Challenges “grind” is too subjective for this post, but the argument is noted.)