You can mention nine things the team did right and mix in one thing that needs to be corrected and some people will think you're being negative. For those who think coaching and keeping girls' psyches in a good condition is not so hard, then I need to come and take copious notes from you. I've coached thousands of games, and believe me, keeping a team in a good frame of mind at all times is not easy. I've seen a lot of coaches who think their teams are harmonious and their players are happy when in fact they are one step from breaking up. If anyone who has coached for any length of time thinks he hasn't been in that situation, then he is fooling himself.
Again, I agree with everything said here, but it's often not that simple. If parents are expecting coaches to do everything as perfectly as it's laid out here, they will be disappointed.
If you haven't been a head coach, try to imagine the following scenario: You have tryouts, choose the team, make some tough cuts, organize the team, plan and conduct several practices, do administrative work for the team, occasionally hear talk from the parents about how great the team or individual players will do (if only the coach doesn't mess it up), and then the first tournament arrives. Inevitably, the team is going to make mistakes and may or may not have a winning record. As time goes on, one or more players is disgruntled about playing time, position, or whatever else, and one or more parents complain in the stands. The coach hears all of this either directly or indirectly. And then the team suffers through a tough weekend and near the end of a 90-degree 1-4 weekend, a player cops an attitude. This is after one of the parents lodged a complaint earlier in the day about playing time or position and two other girls showed up late for warmups. And you think to yourself as the one girl is showing her attitude over sitting out this game and the parents are complaining about the team losing, "And I'm a volunteer here?" At that point, the next thing that happens that you don't like might be enough to set you off.
If one can somehow get through an entire coaching career without anything like that scenario ever occuring, good for them, but they'll be in the distinct minority. But since most coaches will endure scenarios like this, I would suggest that parents need to cut head coaches as much slack as possible. It's hard to describe the pressure a head coach feels, even a volunteer-parent coach. You've got your own set of high expectations and feel an ownership of the team, and on top of that the parents pretty much all think the team is quite a bit better than it actually is and expect the team to pretty much win all the time. When things don't go well, John Wooden might behave perfectly, but most coaches won't. It takes a lot of time and experience to learn to stay calm and weather those storms. For those coaches who don't have a ton of experience, I urge everyone to cut them some slack if at all possible. I realize some things must be addressed immediately, but if a coach blows his top once or twice at the team or parents, let it go. If a coach makes the team run one time after a game because he's fed up, let it go, it isn't going to permenantly harm anyone. If the coach is still doing all of these things on a regular basis after a few years, then it's time to find another travel team or lobby the AD to get rid of the coach.