Anybody answer why or any comments from the community
Their sectors are split laterally vs horizontally, mostly around the departure/arrival routes into the New York Terminal area, or in the case of the airpsace directly overhead which is split directionally (southbound to the west, northbound to the east). Except for BOS and the NAT tracks, there's not many population centers from the northwest through south to feed ultra high airspace, so it's not that busy up there with overflight traffic. With the exception of a couple of far eastern sectors, Los Angeles airspace is set up the same way. Just my 2 cents. DJ