I've got a couple of comments, on both sides of this. First, this year I watched a high school team play all season. Many of the parents were scathing about the coach. I, too thought that some players didn't get the playing time that I thought they deserved (plus and minus.) I had the opportunity to coach essentially the same group of players later in the year, and by the time a dozen practices and games had gone by I realized why the school coach had done what he did, and conclude that he was right all along. So if your opinion of whether or not the coach is playing based on talent is based on what you saw from outside the fence during games, you might think differently if you were on the field with the players every day for practice and in games.
On the other hand, an honest coach will admit that he hopes fervently that the "big booster's" kid will be good enough to deserve to play on his own merits; because if he isn't, the coach is gonna get reamed by somebody, all season long. And if it's a close call; well, yeah, "booster's" kid probably will get the benefit of the doubt. Just reality.
D'oh!