Grant,
Interesting question and touches on something I was noodling on the other day. I am of the opinion that modern courses have greater visual aspects for the most part, because our generation was raised on TV and needs visual stimulation to respond.
TV is still here, but I see kids gravitating to the net and smart phones. Is a possible design trend to appeal to the next generation less on visual and more on what I call "instant feedback?" The Top Golf driving ranges suggest that there might be something to it. I see all kinds of non traditional golfers there, hooting and hollering every time they hit a fw target, and watching to see their point value come up on their computer screen next to their tee. In other words, instant feedback.
Could it be that in the near future, we will retain traditional golf but develop other versions of it to appeal to different people?
And to answer your question more directly, I think subtley is probably on the downswing, again perhaps because of TV requiring the 30 min wrapup and conclusion, time crunch, etc. Not sure that applies to the instant feedback generations, but I cannot see how subltey fits into that culture either.....