I've had a condition to exclude marketing list X in my segment for over a year. Just now, I learned that this condition has no effect on the segment, since it is not a "subscription list". Why do I even have the opportunity to add this conditon to my segment?

Now this leaves me only wondering what other conditions have I used that have no effect on my segments. The default should be that the end user cannot add conditions that do not apply, and not that the end used should test after every condition whether the condition works or not.