PotC was an afterthought at WDW. They didn't build it for opening day, because they didn't think guests from the east half of the country would care about pirates. They guessed wrong, and there was an outcry for PotC and they ended up building it.
They likely didn't go to the same extreme because of space limitations. Half of Disneyland's ride is inside the "berm" while the rest is outside. The drops at DL are to get under the train tracks, and then they lift you back up to unload.
At WDW, only the queue, load, and the opening part of the ride are inside the park. The drop takes you into the show building, which is outside the tracks. To create more show, it would have taken up even more of Adventureland, which, as you know, is already very cramped.