I think MH are games that people will initially dislike, but have to really keep playing to appreciate. It's because the amount of content in it's mechanics is quite overwhelming as a first timer, and inexperienced people will not understand how to make proper builds and have issues.
Also, since it's not like any other games out there in terms of how the combat works, people can find it awkward at first. But, once you get into the groove of things, its quite addicting, and it's a time sink because hunts can take awhile.
I didn't like MH at first, and took a bit of trying to get into it. Many people have similar stories. It's a different kind of game. Due to how the combat is, and the complexity of the game, it has a high skill ceiling.
As far as co-op online play, they hit it out of the park with MHW. Group play works so well. I expect group play to be as good or better with the next games. If you are struggling, you can always SOS and a group of players will join right away for group hunts. As long as you don't have anybody that has too great of gear, playing with others is quite fun. Group hunts are pretty fun.