Because otherwise you could get the quest, recall to the destination and finish the quest within 5 seconds without any sailing (if you already have the fish).
Since you're so against "instant gratification" I think you will understand that sailing should be an important part of fishing quests.
Actually if the quest and destination are both in the following list of cities, you can do this even now:
Trinsic, Jhelom, Skara Brae
There's also a few places where you can park your ship, recall to the dock to get the quest, and if it's to a nearby city, sail your ship across the server line, and deliver.
Example: any of the 3 above, delivering to britain.
a. Have your ship sitting just south of the server line that runs through Horseshoe Island and Buc's den.
b. Recall to the 3 cities in the list above, getting the quest for each.
c. if one or more is to Britain, load the crate up, sail the boat-length or two to cross the server line, then recall to Britain, and deliver.
d. IF you need a Britain quest, get it.
e. If it goes to one of the cities in the list, sail back south of the line, and recall to deliver.
Similarly, all one has to do to deliver in the Trammel lost lands (or get to the fishmonger to get the quest), is use the Serpent pillar, then recall to the fishmonger. Then, once done, sail over to the LL side pillar, and get out, putting some space between you and the pillar. That way, you don't have congestion problems at the pillars or at papua dock.
