Everyone here can send negative karma to anyone by pressing the Karma [-] button, it's very easy and there are no special requirements (POV from my account). I can't abuse this negative karma feature, because to be honest, the users here are very friendly and I often get positive karma which can boost my enthusiasm for posting. Yes, instead of giving negative karma, I would rather give advice to the person first.
Negative karma can be obtained if you have posts that disturb other users. So, instead of writing something to create a negative vibe, it's better to change it so that you only create a positive vibe. Even though it won't give you positive karma, at least you won't get negative karma.