it's strict because the US has no national healthcare and joining the military to get medical care, or lying about issues to get cared for later, is common enou

it's strict because the US has no national healthcare and joining the military to get medical care, or lying about issues to get cared for later, is common enough that it's a concern. way less of a problem in places with socialized medicine, since everyone is already in the system and it's easy to get records pulled -- e.g. check the box during application, wait several weeks, and go. and there is no incentive to screw the military, since you can get that hernia problem fixed without them. also, issuing medical and personel waivers to people who aren't 100% perfect is a way the military controlled inputs; during lean times you issue more waivers, give more people a pass who may not fit the bill otherwise.