It wasn't an experience thing. It was that Bowles' first DC gig in 2012, his defense allowed almost 28 points per game. I mean seriously, they let up the same amount of points as Mel Tucker's Jaguars. I wouldn't have been complaining if he was hired, but I wouldn't have had high expectations.
I just have a gut feeling Austin will be an excellent coach. He has an excellent pedigree as a position coach working some really great coaches. He's seen how they run their teams, and in the last 10 years he's been on 3 Super Bowl teams(05-06 Seahawks, 08-09 Cardinals, and 2012-2013 Ravens).
I watched some of his interviews, and Austin seems to have a really good personality and genuine guy. Couple all of that with the Lions turn around, and I think he will be an excellent head coach if given a shot.