What? I wasn't even talking about mastering the game and how ood I'd be at it. I'm talking about being fun whatsoever. I don't have to master basketball to enjoy it.
I misunderstood - but the point is still relevant.
Bastketball (or any sport) isn't much fun when you don't know the rules, can't hit a shot, and lose every game. Want to change that? Learn the rules and then practice a little bit.
Chess isn't much fun when you don't know how your weapons.. er.. pieces move and interact with the enemy. But once you master the basics, the game is very enjoyable for most people.
Understanding how some activity works and having some base level of skill (often but not always obtained through practice) makes that activity inherently
more enjoyable for most people. So the question becomes how long it takes for Monster Hunter to become acceptably enjoyable...
In my opinion, Monster Hunter is very good very early into the game. You
don't need to play for 40 hours before expecting a payoff - just don't expect the payoff to come when (a) you haven't learned the basics and a half-baked demo throws you into the deep end before teaching you to swim, or (b) you haven't finished early quests that are very obviously intended as simple tutorials.
The first hour or two of Monster Hunter isn't that exciting. That time is spent like a tutorial, giving you access to one or more weapons you'll learn to use, interacting with local flora and fauna, and getting a lay of the land where you'll be hunting. The next 100+ hours just keep getting better as your character becomes better equipped your skills honed, and the challenges asked of you become more exacting.
As a personal note, I was able to get into and enjoy Monster Hunter games much quicker than recent Zelda games or Okami. And by the end, I felt much more empowered than in either of those series.