As an earlier poster stated (luv2run?), this is symptomatic of the problems when school coaching predominates over club coaching. What coach in their right mind assigns training based on a group dynamic. Everyone is an individual and should be treated as such, or please don't coach, you aren't competent enough.
As to the former coach. These kids aren't on scholarship (as in a College setting), they didn't fire the previous coach (presumably) and so should have a choice as to who they choose to influence them, without recrimination. Sometimes American society is worse than any socialist/communist one could be - as in this situation. This is the kid's running careers we're talking about here, the coach can screw up any numbers of people, but the athletes have only one career.
As to the mileage for this individual - perhaps on the extreme side, but again perhaps this is the groundwork for this individual to develop to their potential. Too often Americans complain that foreigners must be on drugs to beat them, and yet certainly some African women do higher mileage quite young - the potential danger (other than injury) is that the athlete might shorten their career. So what, maybe they want to peak at 25, and not continue on until their 30's. Shouldn't that be their choice - as long as informed choices are presented to them.
A couple of facetious (8mile/week program) posts made me laugh, and definitely there is little mention of the physiological variables (LT,VO2max, etc.) involved in training that are actually more important than the authority of a coach. Rather hypocritical for a society that seems to pride itself on the value of the individual and democratic rights of said individual.
Someone mentioned Pete Tegan - to some (Suzy F for example) he was great, to others he was an asshole who ruined their College and sport experienece (I personally know of a some). This is part and parcel of the College "scholarship" experience. He is by no means the only coach with this disparate affect on athletes - one of the problems with scholarship/sport development processes, is that not everyone is on the same page when it comes to athletic developnment, and the athlete is too often in a poor situation (almost as indentured servitude - see tripling at conference meets) for their own personal development in the sport. The price is that they can get a free (or significantly subsidized anyway) education out of it. This isn't the ideal model upon which to lay a sport development process.