Only 4 responses.
be patient
it seems to me that eventually, your kids will get exposed to *bunghole* coaches if they play sports long enough.
My daughter ran into the Bobby Knight of highschool fastpitch softball this past season. The guy wasn't quite as bad as Knight, but even so, he managed to squeeze out most of the fun the girls get from playing. They only lost two games all season, but the way they moped off the field after the final huddle following the last game, you'd have thought they'd only won two games all season.
My son played football for the first time this past fall. Mind you, this is a rec league of 5th and 6th grade kids, mostly, so it ranks 1,873,892,013,562 on the list of big deals. He had some decent coaches who seemed to make it reasonably fun, even though they had a pretty bad team, and Blader Jr is jacked to play again next year, which is a good sign. But there were some coaches out there in that league who won a lot of games and probably the league championship doing the Bobby Knight thing, who I'm sure will have run off at least half the kids who played on their teams.
In hindsight, I probably could have played baseball in college someplace, but I remember quite clearly my very last high school game thinking, "thank god I don't have to do this anymore." Our coach and the summer Legion coaches just had a way of not making it fun to the point you were looking forward to never playing again.
My dad played football at Notre Dame under Frank Leahy and the experience really jaded him. He was a stud high school player, basically the best RB in his city, but after a few years under the golden dome, he could not get out of Notre Dame soon enough.
I guess my point is, Bobby Knight is hardly unique and you'll find him at all levels in sports and it's less a question of "would you let your kid play for him" as it is "how would you advise your kid if he get's stuck playing for a Bobby Knight?"