Not all of the Big10 teams had those schemes. Some were fast and passed like mad...and those that were built like the PAC-10 teams lost when the weather turned cold. Overall during the regular season the Big-10 v. the Pac-10 was pretty even, though a superficial glance suggests that it was mostly bottom-rung Big-10 teams playing (3-8 records show up frequently in USCs games), and a very notable difference in performance between home and away (with victories against mediocre Big10 teams at home being much larger than against poor Big 10 teams away).
A glance at Washington appears to show this too, though there are few examples.
78 RB Washington 27, Mich 20...but lost to 7-5 Minnesota
81 RB got hammered by Michigan, blew out winless Northwestern
82, RB 28-0 over 8-4 Iowa; DNP Big10, but lost 31-0 at UCLA.
91, RB 46-34 over 8-4 Iowa, but squeaked by 2-9 Purdue
92, DNP Big10, but was 12-0
You can find other examples of how different it is early in the season compared to later, like 1974 Ohio State beating UCLA 41-20, then losing 23-10 in the Rose Bowl. You can't make a sane argument that that was from slow v. fast.
From the early 70's to the mid 90's, the Pac-10 won 19 of 23 Rose Bowls. NINETEEN OF TWENTY THREE! Are you trying to tell me that it was jet lag or the sheer hell of having to play in 65 degree weather that accounted for this incredible gap between the leagues?
And...And...And...
It is commercially impractical to have the bowl games in the midwest in January...but you'd see the SEC and southern 3/4 of the PAC-10 get eaten, probably to a like degree (See Tampas record in games below 40 degrees, or New Englands for the opposite extreme). There's reasons the teams in the BIG10 were built the way they have been - it reliably works in the cold and ick. They've spent the last two months in winter, and function best at about 50-55 degrees, and advantageously below that. A Purdue or Illinois passing team falls apart in that weather and doesn't get to the Rose Bowl - not that either was top-notch this year anyways. Tressels teams have been more bowl-built than past OSU teams.
And Arizona State that went 1-1 in those three decades? That streak is almost all USC and UCLA with a few Washingtons stuck in there.
"Not all the Big 10 teams had those schemes, some were fast and passed like mad and those that were built like Pac-10 teams lost when the weather turned cold..."
That's complete baloney. Those lower level Big Ten teams were losers early in the year and late, it had nothing to do with weather. And the early attempts at passing offense in the Big Ten were as rudimentary as the power running attacks they hung onto for about three decades too long. The high schools in California ran more sophisticated schemes. In some cases, they still do.
Over all these years, why didn't Notre Dame suddenly start losing when the weather got cold? They generally play upper level Big Ten schools and they have something like a .680 career winning percentage against the Big Ten. Why have Washington, Washington State, Oregon, Oregon State, BYU, Boston College and a host of other poor weather teams continued to embrace passing offenses and continue sending quarterbacks to the NFL? How did Brett Favre in Green Bay, John Elway in Denver, Jim Kelley in Buffalo, Tom Brady in New England, Terry Bradshaw in Pittsburgh, Fran Tarkenton in Minnesota (I could go on and on and on) put up huge passing numbers and go to Super Bowls coming from such lousy weather cities?
Bottom line is, you embarrass the Big Ten with your excuse-making. Basically you are saying that your league is so soft that they can only compete with good conferences under their terms, in their comfort zone. "They function best at 50-55 degrees"!! Oh God, gimme a break. Ohio State and Michigan just put up about 1,000 yards in offense against each other. I don't remember the weather getting in the way of that WAC-type contest.
And finally, before you try to say USC only played the lousy Big Ten teams, be very clear. 9 of the last 11 times they played either Ohio State or Michigan in the Rose Bowl, USC won. 9 of 11 against the best you had to offer.