There is no global or systematic way to achieve that. People can always become members of programs unless you explicitly prevent it from happening by an exclusion or status changing Smart Campaign.
For example: If a person submits a form that is on a landing page in a program, they will become member of that program. That is just intrinsic Marketo behavior. The only way to prevent that from happening would be a Smart Campaign that removes them from this program if they are a member of your one exclusion program.
I also don't see a workaround. Putting those program members on a list or turn a specific field value to TRUE to for them, would not systematically exclude them becoming a program member.
So probably the best way to approach this would be to ask: What do you want to achieve with this program exclusion? Why are they not allowed to enter any other program? Program Membership in and of itself doesn't do a lot.