He's 31 thanks, and still will be at the start of the Scottish football season! Your ageist attitude is exactly why supreme athletes such as myself have all but given up playing for the Dons.
I suspect that if you looked at the stats from last season, you'd see that Hayes covered as much ground as anyone else in the Dons team, and the way that Shinnie plays would suggest he could easily do similar. In reality though, if we get two good seasons out of him for the price of three, that'd be better than most of our signings this century. If it gives his family security and makes him happy to be here, then all the better. He'll know when it's time to quit when it comes round I expect.