Foley was not the AD in 2017. And if you want to say that he was still influencing the AAD, then how do you explain Mullen? Foley hated Mullen.
Here is how I would explain this scenario given that Fooley was no longer the AD, was or was not pulling the puppet strings or has any say. But what can't be argued is that Fooley's stench still is in abundance, therefore:
Stoops: Has won at the highest level and been at a program with an 80 year history of football and at a place where they care about football and will do ALMOST anything it takes to remain relevant. Upgrade facilities but never short the football program just to catch up in other areas.
Mullen: Had never previously coached at a top 10-15 job and realistically speaking was probably not on anyone's list who might be considered a top 10-15 job. Fooley hated him and I am sure the feeling is mutual, but if you have never had a top 10-15 job, you can't afford to balk at probably the only one who might call you up.
That would be my view on the difference