Iowa State is one of the least appealing P5 jobs.... but there are only ~66 P5 jobs. There are really good football coaches at all levels (FBS, FCS, D3, NAIA, high school) throughout the country. There are about 50 of them who would turn down ISU, and the rest would take the job in a heartbeat.
Pat Narduzzi was a highly respected DC at MSU, and has been interviewing for head coaching jobs for years, and finally had to settle for Pitt. You don't think he would have taken the ISU job 2 years ago?
UCF? Go undefeated at UCF, and you make an "access bowl". Lose one game at UCF, and you're in the BBVA Compass Bowl. Go undefeated at ISU, and you're probably in the CFP, otherwise an access bowl. Lose one game and you're playing in an access bowl or some other good bowl.
So, there are good coaches all over the place. Pollard's job is to find a really good one and hire him. Easier said than done, but Iowa State's national perception is not holding him back from many candidates.