As you suggest, a lot of people are approaching it purely from an age, standpoint. My biggest concern with Baer, is also his age. However, unlike the viewpoint from a lot of people worrying about him relating to young players, I'm more concerned that at 66, he may have the approach of "been there, done that, already wore out the T-shirt" and not really have a whole lot of drive. I mean, really, what does he have to strive towards at that age? Is he going to put in 2-3 hard years for us, expecting that a bigger, better, contract will come along that puts him across the 70 benchmark?
Certainly, coaches do coach into their 70s, but most of them are continuing a long tenure at the point where they turn that decade.
I think a lot of people are big on Tim because of the connections. Personally, I would prefer a younger coach, who has a reason to want something to prove, rather than someone like Baer who is more likely coasting into retirement.
However, this isn't the place or time for Tim to make his mark. Working under his dad was fine earlier on in his career. Now that his foot is in the coaching door, he needs to make his own name. If he came to Montana now, he wouldn't get enough credit for his results.