For all the criticism (most of it deserved) that Tom Fazio receives on this site, I believe he needs to be the answer to this question. He has to be seen as the father of the golf retirement community--at least in the US. And, until the recent collapse of the second home market, I would guess that more new golfers came into golf as the Baby Boomers retired and moved to second-home golf communities. This would especially be true for women golfers, who began to play golf in retirement.
Fazio's courses may lack in imagination and creativity, but they are fun, relatively easy, beautiful, and welcoming to new golfers. What I would characterize as his consistent style in general terms--scooping out fairways to make the ball come back into the center, fun minature golf-style greens, ample space to build many homes overlooking pretty views of courses, long runs between greens and the next tee to ensure that golf carts are almost a necessity, etc.--is certainly conducive to bringing in new golfers.
So, whether you are critical of the end product or not, I think you have to conclude that golf retirement communities produced more new golfers in the last decade than any other trend, and Fazio is the logical answer to the question at least in recent times.