I didn't see anyone punished, but there is a definite shift in the way you you are viewed/and or treated once you put in your papers to get out (at least on the non-medical side of the house).
That said, I let everyone know I was getting out to attend medical school. Most of them thought that was an equally honorable thing to do.
Life changes, people get out for many reasons, most of them are good reasons. There are many who would go back in as well (maybe not as many who wouldn't go back in though 🙂
If you have served even for a short time in the military you have already served your country more than the vast majority of people out there, so good on you, even if you get out after your initial obligation.