"Emo sucks" is a popular slogan spoken among the largly popular and happy, Un-emo, white, teen population. It was created as a response to the Emo counterculture that plagues the suburbs of the united states.
Hey emo kid, if you kill yourself now you might get a full page in the yearbook, EMO SUCKS!
"Emo sucks" is a statement of fact in the same sense as "oxygen is good for breathing." "Emo sucks" is now the modern version of "disco sucks," with the all-important distinction being that enjoying disco in the nostalgic, silly sense is fun, but emo will never be cool.
Teacher: "Class, can somebody give me an example of indisputable fact?"
Student: "Emo sucks!"
Teacher: "A Plus!"