I like both styles but don't really know which is better for the sport in the US. Freestyle does allow for a smoother transition to International and Olympic competition, but that's such a tiny fraction of people in the sport.
Folkstyle might have broader appeal at the college & prep levels because it teaches better overall self-defense skills and is more accessible and useful for folks who come from or want to get into MMA or BJJ. Freestyle development is important, but I can see folkstyle being a worthy counterbalance at the college & prep levels. So why not both? I don't feel the same way about Greco, though.