Stupidity. Lack of knowledge of stylistic matchups.
I actually put a couple hundred down on Iaquinta before that fight because, while I expected Khabib to win, I knew Al was a bad matchup with high level TDD (stuffed Kevin Lee 7/8 times) and dynamite in his fists. The odds were way too skewed in Khabib's favor so I could have made a KILLING. At the very least I knew Al would make Khabib look less invincible.
Conor on the other hand has great striking but weak TDD so I think Khabib is just going to walk right through him.
If McGregor and Iaquinta fought on the other hand, it would be a bad matchup for Al.
Styles make fights.