Wayne,
No question its changed, but IMHO, for the better. If you don't like the aesthetics, you would, as a superintendent like the results!
First off, I think many fail to realize that the classics have added tons of drainage pipe over the years in long swales that didn't drain as well as you may romantisize they did. Often, the super added 4" french drains, which as Tyler says, don't work well, and even if constructed well, will clog and require maintenance over time. Basically, the "modern theory" is, if its a surface drainage problem, solve it with a surface drain (ie catch basin inlet rather than french drain)
Here is how my surface drainage design has "improved" over the years, based on experience, the ability to get the course open quickly and in good shape, and just good old common sense observation:
1. Water concentrates into stream flow at about 300 foot of run. Place drain inlets at 250 maximum runs to prevent erosion during grow in.
2. Sod holds water! If there is any inkling that we will sod an area, it needs to be graded to 6-10% slopes, even if the natural area is a traditionally "sound" 3%.
3. In seeded areas, even 3% causes problems sometimes (shifting soils, etc.) so plan to grade those to 4-6%, knowing that some areas will require slower slopes to make things work in the field, so leave some wiggle room.
4. Cart paths block water, and standing water, when run over by cart wheels causes problems. Grade raised paths, and add lots of basins and pipes on the uphill or both sides of the path, since it is the most heavily trafficked part of the course. Incidentally, once water collects on a path, you can never let it get off the path, as the erosive force is just too much for turf to stand up to.
5. Treat fairways like an engineer treats a road - swales on both sides, inlets to carry water below as necessary, so no drainage except what falls on them crosses the fairway.
6. Remember, many environmental reggies now require us to move water away from natural outlets to let it settle out sediments before entering streams. Like it or not, this often means grading much of the site.
7. Don't skimp on pipe size! Because the capacity of a pipe goes up the square of the diameter, ( a 6" pipe has a sq. inch cross section of 3x3x3.14, or about 27.3 sq. inches, while a slightly more expensive 8 inch pipe has 4x4x3.14, or49 sq. in., almost twice as much for about 45% more cost) Larger pipes can also be laid on shallower grades, which often helps out tremendously!
There is more, of course, but you can see that we deal with things like more sod, cart paths and environmental restraints, the public perception that a new course should be perfect - no time to slowly fix drainage problems - compared to courses years ago in the Golden Age.
In short, designers in both eras designed to the technology available and the expectations prevalent. In that way, they are equally good drainage designs. As noted, I believe current drainage designs are the best ever, technically. I agree that seeing more basins on the golf course can be a distraction. I would complain more about that, but in fact, I rarely can recall taking a drop from a basin that affected play, even in a greenside chipping area or center of the fairway, so I think its a good trade off.
Also, I think TEPauls point about natural slopes is probably a separate issue. You can have very natural and flowing 4-10% slopes across your golf course and have good drainage with a natural look. Its the 20-33% mounding that often looks unnatural.