I've always been of the belief that committing to one sport so young is a terrible idea. All research shows that kids need to be exposed to multi sports until they are at least 12.
I agree it's best in the ideal. It's also why some say historically the US has produced some world class keepers-- because of all the catching they do in other sports. But there's also a bit of a prisoner's dilemma here, as pointed out by the fact that kids seem to be going club (and DA) younger and younger. Soccer is part talent, part hard work...you get better by getting more and better touches on the ball. So the kid at age 10 who is doing GK training with a coach that knows the little details is simply going to be better than the kid at age 10 who has great natural talent but may be coached by someone who has no idea what they are doing at goal. The competition for college admissions (not just in sports, but also in academics and things such as fake charities which all the kids seem to have now days) has made it an arms race so parents are panicked their kids may fall behind, particularly if they aren't "naturals" at the sport and able to catch up to the others quickly.