I had a parent once email me about his son's playing time in hockey. I approached him in person and during the conversation I asked what he expected. He said "fair play..." You see he had been timing his son's ice time. I noticed that although his son did in fact have rather short shifts, he got on the ice quite frequently; essentially evening things out. He obviously didn't bother to count that data... I asked if he had timed all the other kids, he said no.
We had a team with 4 sets of forward lines, and 3 sets of defence. Anyone who knows minor hockey will know that that's like an NHL lineup. I had to manage those 4 lines as best I could. 3 15 minute periods isn't a lot of time to roll through 4 lines. So basically everyone got really short shifts, like 30-45 seconds. Sometimes even shorter.
I tend to use the atmosphere on the bench as a litmus test for how well I'm doing. If the kids are happy, then things are generally OK. I couldn't care any less about what the parents think of my coaching style because they're not out there with me.