Fair enough.
I think at a school like Purdue that doesn't have the depth of helmet schools or near helmet schools (LSU), and usually only has 1 or 2 really good players on both sides of the ball with excellent schemes is going to suffer pretty badly when those 1-2 really good players on both sides of the ball sit out and when the mad genius x's and o's scheming it up and his staff are all gone off to another place.
Overall I agree, but just for the record, Purdue has/had more depth than LSU, who was still somewhere between 15-20 schollys short this past season. They have the least amount of scholly players along with ASU, by far fewer than any other team in the country. They had a whopping 39 scholarship players available for last year's bowl game when we got our ass kicked against K-State. Now, there were some opt-outs and injuries and an academic problem or too that accounted for some of that, but Orgeron left the cupboard really bare. Kelly had a great first cycle, but we're still way shorthanded compared to everybody not named Arizona State.
Also worth noting LSU technically had more opt-outs and players who didn't play the bowl than Purdue did.
....all that said....
Purdue was absolutely hurt much worse by their opt-outs than LSU was. LSU lost almost their entire defensive line, which wound up not hurting them much, and some others who were meh. It might have mattered if Purdue had more of its offensive players. But Purdue losing their QB, best WR (maybe best 2 WRs....not sure), and I think the top back.....you can't even count that as the same offense that Michigan played a month earlier in the B1GCG.
The way that game went, I don't think Purdue would've won anyway because those offensive players weren't going to tackle LSU's players running up and down the field, but having their first-string offense 1) likely scores more points, and 2) possesses the ball more such that LSU has less possessions and opportunities to score. Like I say, I'm inclined to think LSU still wins, but maybe something like a 42-30 affair rather than the dud we got.
LSU's defense is not as good or as deep as Michigan's.....reasonably, Purdue could be expected to score more on the Tigers than they did on the Wolverines.