Are you really that obtuse?
It's not that if he leaves, he gets diddly. It's that if he leaves you for another school, he pays no penalty and neither does the school hiring him. The intent of a buyout is to make it less attractive for a coach to consider a job at another school. If Meechigan State has to pay bammer $5M to "steal" Saban, they may consider someone else instead. It is a punitive measure, bonehead. If he leaves, it will be because someone else ponied up more money than bammer and he could give a shit about whatever he might be leaving on the table in Tuscaloser. It is all about the benjamins, not about whose logo is stamped on the check.
So in other words, when he gets tired of putting up with y'all's inbred shit, he can leave without so much as a kiss and a wave good bye, the next school in line can throw all of its money at his salary without worrying about a buyout payment, and you guys are left holding the bag again...