The draft was very selective. You could evade service for any number of large or small reasons: religious, bone spurs, color blind, eyesight, hearing, flat feet, college enrollment or because your family had the political or financial pull to defer you). It was anything but fair and it meant that those who were drafted into the Vietnam War later on became nothing more than cannon fodder.
I must take exception to your application of 'evade' to all cases, although I can well understand why many, particularly those who served in the military, would agree with you. To me, evade applies to those who fled the country, went into hiding, or faked physical infirmities and religious convictions to take advantage of the law. For those who, like me, complied with the law, avoid is the correct term. I didn't evade the draft but I did avoid it. I conformed to the requirements spelled out for a student deferment, an occupational deferment, a family deferment, and finally was awarded a high number in the draft lottery. I'm not proud of not having served, but when you're 20 years old and Congress made it easy to get deferments, and you were looking at the possibility of getting shot up in an Asian jungle, taking advantage of deferments was an easy decision. When I went to college it was not limited to financially well off families. My dad had been dead for years and we were a poor family. National Defense Education Act loans, private loans, some scholarship money, and work paid for my state University education. My older brother, who was rejected when he reported for his draft physical because he was in veterinary college, and I decided that Uncle did not do us any favors with the readily available student deferments.
The draft was unquestionably skewed in the demographics of the ones who got drafted, but don't blame the young men of the time, blame Congress. They made the law.
Years later a retired Army Colonel told me to never think I did not do my part in supporting the military. I spent 7 years working for the Army overseeing the quality assurance programs of ammunition production. He said making sure the ammunition sent to the troops was correctly manufactured was a very important contribution to the effort of protecting our country.