Most beginner scuba divers want good viz, warm blue water, and colorful fish. In the Continental U.S., I think some part of the equation is that this is really only consistently available in S.E. Florida. For most of the other 47 states, S.E. Florida is a plane trip or super long drive (about 12 hours of driving from me in Tennessee). For most, this makes scuba a vacation sport rather than a consistent hobby -- and consistency makes one more comfortable, and then more passionate about it.
Contrast that with ski resorts from Maine down to Georgia and across to California -- most of the U.S. lives within a manageable weekend drive of some skiing that's at least halfway decent. Same can be said of golf (available in about every city), making both golf and skiing easier activities to participate in than scuba.
Sure, I now like murky quarry dives, murky Gulf dives, etc., but it was warm blue water, clear viz and colorful fish that got me into the sport.