Obviously it would be better to keep things as-is, with non-employer-provided insurance ranging from difficult to impossible to obtain at any price :)

Well, maybe it's not a downside. One could argue that young men have life on easy mode and should be the ones to bear burdens that their advantages let them handle more easily than others.

3 points: 1. those others groups with smaller percentage increases currently pay higher premiums. 2. Young men become old men. 3. Young men actually are more likely to have risky behavior that leads to them becoming old men that take money out of the system.

All of these are basically part of the nature of insurance - pooling risk.