At least one of the wars you say was won with a draft (WWII) was won with people mostly willing drafted.. a far cry from Vietnam. Even in WWI, it was treated as an adventure and many enlistees were eager to go.
Except for basic training, my father spent the entirety of WWII in combat. Except for a short trip home to get married, he didn't return home until 1948 from Germany where my sister was born. Later after I was born, he was sent to Korea. I was in 68-76 and my impression is different than your father's. From what I say in my 6 odd years while they had the draft, the attitude of the draftees was piss poor, period. During Vietnam, most of the draftees didn't want to be there, they were just looking for their time to be up. Vietnam was probably the first war where soldiers were not fielded until the duration.
This army of today (all services) is vastly superior to the Vietnam era, period, even if they are still only deployed in combat areas for a year or less..
My dads experience is also effected by the fact that he was in a Pershing Nuclear Missile unit. A Pershing Battalion had about 1600 men and because of the jobs had lots of college educated draftees. My father says most were happy to be there rather than in Viet Nam, and most wanted clean records when they got home.