It depends on what the military person was discredited for. If it was something minor, or not harmful to other human beings than I think they should be allowed to be public speakers. If they did something criminal and terrible than no they should not. It depends on the situation.
I believe discredited military personnel should be allowed to become public speakers. Anyone who wants to become a public speaker, should be allowed to do, just that. The problem with becoming a public speaker is having an audience. In reality, the audience decides if you can have that position, because if you are not good at it or qualified for it, no one will listen to you.
Yes, discredited military personnel should be allowed to become public speakers, because they are an important part of the national debate about the United States military. The person might have some insight that will change the public's opinion about the military. However, it is important that the person not divulge secrets that could hurt the country. That would be penalized or charged criminally.
Well, if they are discredited, isn't it obvious that they shouldn't pose as honorable military people, go on tours, speak, etc.? The only exception would be if they have somehow earned their honor back, and are willing to share the whole story. When people come to listen to military heroes, they want to listen to military heroes.
Actually, no one who has been discredited as a professional or who has been convicted of a crime in his or her job should be allowed to make money on that profession by doing public speaking, and that includes military personnel. However, that is not going to stop this from happening.