If the head coach the player committed to leaves, I give the player a pass on transferring. Everyone talks about how you should commit to the school & program and not the coach but the reality is the coach is a huge part of the equation.
I agree with those who say you should have to sit for a year when transferring (unless there's a head coaching change involved). The WCHA (and other conferences?) have the rule and it seems to have worked fine. If a player is really that miserable at the school they chose, sitting out a year while still maintaining four full years of eligibility should not be a barrier to transferring. (Worked out fine for Schammel going from Mankato to MN for example.)
Also, the younger generation seems to have a penchant for easily leaving when the team, program or job doesn't turn out to be everything they've hoped. I see it in youth and high school hockey all the time as players leave their home associations and high schools for supposed better programs and it certainly carries over to employment where changing jobs two or three times in two or three years is not unusual for them. Of course, parents are playing a role in allowing/encouraging the younger kids to leave for greener pastures as the parents think they're kid is the next big thing and "deserves better."
In the end, making transferring just a bit harder for the players isn't a bad idea. Trying to work through some discomfort is better in the long run as things may absolutely turn out to be great after the rough patch. It's definitely something I've tried to teach my older teenagers...with mixed results...