Great analysis and your 100% correct. The Big-8 and South West conference suffered from the same problems especially when the met up against passing game and super fast defenses of Miami.
The SEC has always relied on speed and athleticism on both sides of the ball pretty much since the days of Bear Bryant. They can be pushed around at times (Nebraska vs UF in 1995) or passed into oblivion (USC vs Arkansas), but they generally hold up pretty well.
The SEC embraced the pro style offenses in order to keep up with Spurrier's UF teams but since he left, they have returned to a more ball control type style of offense.
I do believe that climate determines to a large degree what sort of offense a conference will gravitate toward. In the Big-10 and especially then Big-12 North, the winter conditions really require the ability to grind the ball out on the ground as passing in those conditions, especially by a college level QB, can be very challenging.
The weather does have something to do with it, but Washington, Washington State, Oregon and Oregon State have generally had fine passing attacks despite playing in a lot of lousy weather. Notre Dame has had great passing attacks for 30-40 years, and they are located right in the middle of Big 10 country. John McKay at USC and Bill Walsh at Stanford had much to do with the Pac-10 throwing the ball a little earlier than most other conferences. Then, over time, more and more teams started to realize they could compete with the better programs by throwing, it was an equalizer. The SEC has kind of been varied over the years, but generally more physical than finesse. But they have benefitted by Spurrier's influence, Tennessee has had some good passing offenses, and then even more recently by Auburn getting Borges from UCLA (and going 12-0 that first year in 2004 with a balanced offense) and then even more recently by the circus offenses that Florida and Arkansas are bringing to the league. That league will be even better as a result, because the other programs will have to ramp up to answer these different offensive approaches.