Jeff,
You say: "If you challenge a strategic bunker to gain advantage, and get in it, and it costs you three shots, you aren't going challenge it very often. While that is strategy, the best strategy is tempting, one that doesn't virtually shut off your options because its too difficult to recover. And, there is great joy in pulling off a recovery shot. Dropping out is no fun at all."
By your argument, you must really hate all those pot bunkers at this place called The Old Course. As such, if you state that being forced to chip out because of a tree limb is bad design, then I'll state that being forced to chip out because of a sod wall is also bad design. (Of course, I don't think either is true).
But really, challenging a bunker will always mean "coming as close to it as one dares." You can skirt a relatively tame bunker by 5 yards, or stay 50 yards from Hell. The number of shots you think it will take to extract yourself from a hazard does not increase or diminish its strategy. You will always be TEMPTED to hit it closer. It goes back to Tom Doak's description of the fairway bunker at the 12th at North Berwick. A golfer will, over a number of rounds, creep closer and closer to that bunker, until the day he falls in. The next day, he will stay well clear, but soon begin the process anew. That, in my books, is great architecture. And it doesn't matter how severe a punishment, given an appropriate reward, one will always push the envellope to see how much we can get away with. It's human nature. The "appropriate" reward or the punishment are very individual values. In fact, I recall Patrick Mucci himself, a while ago, telling me that (according to him, anyway) strategy is improved with a deeper, more penal bunker, whereas I argued that it merely changed the strategy without it becoming better or worse. The strategy and temptation will vary, depending on a myriad of factors, not the least of which is the abitility and character of each player.
Of course, the first counter-argument to this would be that, if the punishment outweighs any possible reward, one is likely to say "The hell with it", stear clear of danger, and settle for a bogey. Yet that is the basic concept of strategy: Offer a reward for those willing to accept the risk. But give others an easy route to the green, without risk, but without reward."
On another note, I also don't believe that proper design is limited to a two step penalty, as you stated. Or, in other words, that the punishment should be proportional to the miss. It goes back to MacKenzie story about the fairway bunker that was way right of the landing area "to punish the severe slice". Designing this way is connect-the-dot architecture. Hit here, and then there. Target golf. Darts, if you will.
I often compare the difference between strategic golf and target golf to, oddly or appropriately enough, a game of archery with two targets. Target golf is the conventional game with the conventional target. 1000 points for the bulls eye, then 500, 250, 100, 50, etc... Strategic golf, on the other hand, uses a different target. Instead of getting the most points for hitting the bulls eye, you LOSE points. How many points you lose will not make the game better or worse. Just different.
As such, the game is not one of mere execution, but also becomes one of strategy and temptation. How close do you dare?....