If not for that, most DT members would easily tag anyone who disagrees with their point of views.
Theymos addressed that already:
The system is for handling trade risk, not for flagging people for good/bad posts/personalities/ideas.
There are people who love power and won't hesitate to use it on others unjustly.
Tagging people doesn't give you power,
not caring about their opinion means they have no power over you. Can you imagine many people
choose to let some anonymous person somewhere on the internet make them feel bad?