Why is it that concern is so often interpreted as jealousy? Are you guilty of this?

It seems that whenever someone offers advice to a friend about a person in their life they disapprove of for whatever reason, it comes off as jealousy. Why should we even have to wonder? What’s so strange about being concerned? Must there be an ulterior motive? It seems like people are quicker to assume someone is jealous rather than caring. Do you do this a lot/are you a victim of this?