You may be right... However......
And maybe THAT is a reason for the high attrition rate. Are there a lot of people out there who Dive far from the sea where it becomes a HUGE effort to get out to Dive? And if so, maybe it is hard to maintain that connection to the sport far from any tropical waters (though I am sure there are a number of dry-suit Divers who might disagree). After all, in a comparable sport dynamic - skiing - you are rarely more than 4 or 5 hours away from a place to ski, right? (my apologies to Texans on this who might be a bit further than that..)
I *do* believe, where diving is concerned (at least for *me*), you're either smitten or not...
I will go to the Keys, or Lauderdale, Jupiter, Bahamas, Coz, etc. whenever the opportunity presents... But, if it doesn't, and I've only got a day or two, I have absolutely no problem heading down to the quarries, where it's colder, the viz sucks, and the sunken firetrucks, motorboats, and porcelain thrones are all there is to see... I don't care... If I'm not there, I'll read about, and plan the next trip... or kill a few hours on this board, almost always picking something valuable up I didn't know... I rarely pass my LDS without stopping in, and picking up a useless dangly...
Point is, there are obstacles. Always will be. More for some than others... But, if you're smitten -- doesn't really matter how often or what the conditions are... You'll stay connected...