Dinghy Sailing Show

The RYA Dinghy Sailing Show is this weekend in London. Why isn't there a boat show like this in the US?
I remember going with my Dad to whatever version of this show that existed in the late 80's. It was incredibly exciting and overwhelming. They had a huge pool (with fans for wind) right in the middle of the show with actual sailing demonstrations going on. I can't accurately remember if I actually got to sail an Optimist at the show, but I do remember putting on a cold damp wetsuit and getting ready to sail.
The exhibitors at the show include the class associations of many dinghy classes that don't even exist in the US:

29er Class Association
29er Youth Class Association
405 Uk Class Association
420 Class Assoc. International
420 Youth Class Association International
49er Class Association Uk
505 Class Association International
Albacore Association National
B14 Class Association International
Blaze Class Association
Boss Class Association
British Moth Boat Association
Buzz Class Association Uk
Byte Class Association
Cadet Class
Canoe Association 10 Sq Metre International
Cherub Class Owners Association Of UK
Comet Class Association
Comet Dinghies
Comet Trio Class Association
Comet Versa Class Association
Contender Class Association British
Dart 16 Class Association
Dart 18 International Association Of UK
Enterprise Association International
Europe Class Association International
F18 Class Association
Finn Association British
Fireball Association Uk
Firefly Class Association
Flying Dutchman Class Association International
Flying Fifteen Association British
GP Fourteen Class Association
Graduate Class Association National
Gull Class Owners Association
Heron Dinghy Class Association
Hobie 16 Class Association
Hornet Class RYA National
Hurricane 5.9 Class Association British
International 14 Class Association
International Moth Class Association
ISO UK Class Association
Javelin Association
Kestrel Owners Association
Lark Class Owners Association
Laser 2000 Class Association
Laser 4000 Class Association
Laser Association UK International
Laser Pico Class Association
Laser Radial Class Association
Laser SB3 Class Association
Laser Stratos Class Association
Laser Vago Class Association
Lightning 368 Association
Merlin Rocket Owners Association National
Miracle Class Association
Mirror Class Association
Mirror Youth Class Association
Musto Performance Skiff UK Class Association
National 12 Owners Association
OK Dinghy Class Association International
Optimist Class Association (UK)
Osprey Class Association
Phantom Class Association
Ravenspring Ltd
RS Feva
RS K6 Class Association
RS Racing
RS Vareo Class Association
RS Vision
Rs200 Class Association UK
Rs300 Class Association
Rs400 Class British Association
Rs600 Class British Association
Rs700 Class Association
Rs800 Class Association
Scorpion Class Association National
Shadow Association
Shearwater Catamaran Association National
Signet Class Owners Association
Snipe Class International
Solo Class Association National
Spitfire Association
Splash Class Association
Sprint 15 Association
Squib Class Association National
Streaker Class Association
Supernova Class Association
Tasar Class Association
Topaz Magno
Topaz Omega
Topaz Race
Topaz Taz
Topaz Tres
Topaz Uno
Topaz Xenon
Topcat Catamarans
Topper International Class
Topper International Ltd
Topper Youth Class
Tornado Association International
UK 3000 Class Association
Vortex Class Association
Wanderer Class Owners Association
Wayfarer Association United Kingdom

Compare the RYA list above to the list of exhibitors from the New England Boat Show held last month in Boston. The New England Boat Show list consists mostly of boat dealers, boat manufacturers and marine supply companies.

How did dinghy sailing in the US become so concentrated in a few relatively boring classes? Is the large size of the US detrimental to the success of new dinghy classes? Is the US just a nation of lazy powerboaters and cruising sailors?