Based on what. As big as a weight advantage Jan had, Izzy wasn't completely out of this fight. Until he landed the take down in the fourth, it could have easily went either way. Hell if they fight again, and Izzy actually bulks up some, I could see him winning.
Izzy underestimated Jan's striking, and he seemed slower, he should took a fight or two at light heavyweight instead of going straight for the champion, but I think Dana White put him under pressure, because these UFC cards have been trash and he wanted to create some big fight nobody asked for