Jim - if you were exposed more to links, or links-style, courses, you would probably find it easier to understand the rationale for the ground game. Often the courses are hard and firm, so are the greens, and the slopes on the greens mean that balls run off them easily. In these circumstances, hitting the ball in the air and hoping to get it close quickly feels impossible - you just KNOW that you will lose control. So the ground game is a necessary response to courses where you find these conditions.
And when you think about conditions and the ground game, think WIND - the ground game is in significant part a response to the prevalence of strong wind at links course, where putting the ball in the air is a hazard.
Certainly courses where the ground game is a live issue will often play shorter, simply because the balls runs so far. So the main challenge becomes one of control, not of power.
Part of the reason this site esteems the ground game is because it is felt to be more in tune with the origins and traditions of the game. As such, it is seen as the antithesis of target golf - heavily watered, yardage driven, grip and rip it, corporatised, commercialised, commoditised etc etc golf.
Another reason is that it requires more imagination - you can't just say you are putting your 9 o'clock swing on your 60 degree wedge and therefore ball travels 46 yards. You might say that it appeals more to art than to science - in terms of how you execute shots. So I think the answer is that it is probably more difficult to control shots with the ground game - but it is that very uncertainty which is the challenge you should welcome.
A further factor why people might like the ground game is that while (in terms of approach shots) it does not exclude the aerial route, it allows people to hit it along the ground if they choose. So it offers a choice. By contrast, if there is water or a big bunker in front of a green - there is no choice, you have to carry the hazard. So there is less thought involved in the type of shot you might hit - and this type of hole may be very difficult for weaker golfers.
To your final point - it is probably not true to say that any course is "exclusively" a ground game venue, but it certainly is the case that when a links course is firm and running, a golfer unfamiliar with the ground game is going to have a very hard time!