1. Your analogy makes no sense. No extra action is required on the part of the person making/clearing the mark.
2. There's already an option to hear when a mark is placed on a person.
3. I never argued for it to be included as an option, I merely pointed out that your argument is flawed. Personally, I'd like this change it if happened, but I agree with you that it's not sufficiently beneficial to warrant development time (not that it'd take much - maybe a line of code, the rest would be QC/project management time).