Because people have it written down now how it should be said and now call it a rule.
Explanation:
When people make a rule they like to stick to stick with it, so if they were to have English say as an example and use the word stick, they would not like for you to say it any other way because its how it says it in the rule book"dictionary"
Unrequited love resulting to broken relationships or heart can be or could correspond to death. It may seem overly rated but this happens in real life as emotions play a big part to a person's well being. This is what makes us human.
