It's still using a created object and scripts to work when it could potentially be counted as a feature that needs to go with the engine and events system - an entirely new event had to be created specifically to make detecting players in water work, for instance, when it should probably be put with onPlayerTouch.
The physical zone is a good call on the water thing, because it supports all the same calls as a normal water block, with minimal effort required to make it work. onPlayerTouch is used to signify a player colliding with the outer edge of a brick. Water bricks do not have collision by default, so it would not be appropriate to combine the water entry events with it. The water entry events, by the way, are made possible because of the water block callbacks made available by the physical zone.
Physical zone exist entirely to support areas with different environment conditions. Not making use of them for areas you want to be water would have been like reinventing the wheel. Triggers are not necessary to detect vehicle collision. The game already does this. Badspot just needs to expose some of that functionality to the script.
