"Reputable" means different things to different people.
The best coaches aren't necessarily those with the best records, or those whose players or parents like the most. In my opinion, the best coaches are those who teach their players the most about both the game and about life (e.g., sportsmanship), and who get the most out of the talent that they have to work with. As Crystle implied, opinions of parents will be heavily biased based primarily on how much and where their child got to play, and the record of the team. Parents hate carting their kids around all summer and then watching a team lose a lot, and will almost always blame the coach for that and not consider for a moment the talent level on the team, or how hard their own child is working on their game.
Things like managing the game well, communications with parents and players, and winning and losing with class are extremely important, but vastly underrated in my opinion. Fortunately, many of the coaches of the top-talent organizations earned their way there, but a few are jerks and/or only care about winning. In my mind, the best way to decide about which coaches are reputable is to objectively watch them in action (practices, warm-ups and games), and to have a face to face talk with them about their coaching philosophy and approach ... judge them the same way you want to be judged and the same way you judge other people in your life (i.e., employees, contractors, politicians, etc.).