So you say that for the game to be on PS4, the franchise would need re-inventing so it's not going to happen, but you want the game to be like Destiny? I don't think I need to point out the irony here.
None of that data points to "people must have bought these games for local co-op, then". All it tells me is that Non-Monster Hunter hunting action games don't do Monster Hunter numbers, which is common sense anyway. There could be and likely are a number of reasons why those games didn't do well on PS4. To pin it on millions of people upset with the lack of co-op is just seeing what you want to see. It's never that simple.