Forcing cross platform players to buy the original game has some merit when you put consoles into the mix. But given that this is a subscription based game, forcing these people to then purchase an expansion per platform is pretty hilarious.
SE's finance department really are doing there best to drag Yoshida's hard earned name through the mud for every penny it's worth with these moves. I've been playing MMOs since Ultima Online and I have never seen a pricing structure even remotely as toxic and disrespectful to the player base as Heavensward.