The reason why the western market had no interest in past MH games was because of the obtuse systems and the restriction to handheld platform.
MHW has added tons of quality of life improvements and is now available to all three major systems and still maintaining the spirit of what makes the game great.
That's great an all, but improved controls are the hardest thing to sell to an uninterested audience.
People have to want to play something before they even give new control and QOL improvements a chance. And as of right now, that audience is not there.
Maybe a sequel to MHW will reap the benefits, but unless the game literally is lightening in a bottle, it' n going to be as big a success either in Japan or the west as the previous titles, despite costing alot more to make.