Mike,
In my mind, the questions asked have not only to do with shot variety, but they are more internal questions, which is what great courses ask. They create doubt, they question your game as a golfer to stay within the limits of your ability and tempt you to take risks that are not statistically probably in most instances.
Where Muirfield shines is in its ability to question a players pride. I’ll give you one example the 15th hole. To me, this is one of the stronger holes on the property. Off the tee, players are met with three diagonal bunkers that slowly get further away from the tee the more a player tries to chew off. Depending on the wind, players must decide how much they want to take on, and are nervous to be too cautious as it will likely mean this meaty par-4 turns into a 5 in the prevailing wind.
But! If players play too cautiously, they then need to contemplate whether they are to take on the narrows bunkering, which is perfectly placed well short of the green. In the prevailing wind, players have to decide how much to take off the tee, specifically so they could make an attempt at carrying the narrows bunkers. If they decide the risk is not worth the reward, there is ample space short of the narrows that will allow the hole to be played as a 3-shotter, but at a price! They will still be left with a 100 yard shot in the wind to a sloping green. 6 suddenly comes into the equation, whereas if they carry the bunker, even if they don’t reach the green they have a much easier route to a 5.
Where Muirfield maybe shines better than most is that the hole is just as good downwind! Downwind, the players really need to press up the left side if they are to avoid the right fairway bunker, which is perfectly placed. For those becoming too aggressive, there is a hungry bunker on the left that awaits players as well.
The importance of the tee shot is not only to avoid the bunker, but to have a short iron into the green. Because, downwind, you really need to challenge the narrow bunkers to allow the ball to stop on the green. If you play it too long, the firm green will not hold the golf ball, and it will end up in the well placed green side bunker on the back left or right.
For those players that play safe to the middle of the green, they can either use the spine to their advantage, or watch as they will be faced with a tricky 2-putt.
I believe that every hole at Muirfield offers the same type of decisions as the 15th. The issue, which you’ve hit on, is that the average golfer doesn’t play golf as a thinking sport. They are happy to be spoon-fed simple golf with spectacular views. To steal a friend’s quote of another course - Muirfield is like playing chess, whereas Dunbar would be like playing checkers.
On the discussion of quirk, I believe that quirk in itself does not make great golf. Quirk can enhance the strategic / heroic merits of a course. As an example, the 13th at North Berwick is quirky because of the wall, but it’s great because of the bunker placement and green shape. Hitting over a wall is fun, but only if the challenge is stimulating. To illustrate this point, players hit over a wall on the 3rd hole as well, but nobody talks about that much because the strategy of the hole is less nuanced than that of the 13th.
Quirk is an easy thing for the masses to identify as ‘fun’ and therefore, they believe it must equate to greatness - and in some cases, that is true! But not all quirk is great, just like not all tough courses are penal.
Some of my favourite courses have lots of ‘quirk’ and I count them as some of the best courses in the world (NB, Prestwick, Machrihanish, Brancaster, etc), but even with those courses, Muirfield doesn’t have a hole as weak as the weakest at those places.