Okay... I need to clear something up here...
It's this: There is no such thing as 'screamo'! That's not even a word. That's just a
term that people who know no other music than pop label any song or band who
screams. It's dumb.  Screaming is just as instrument. Like vocals or a guitar. Any
genre can add screams into the music. It's not limited to hardcore, metal, and
deathcore (althought that's obviously mainly where we here it). Jeez, a rap song
could have screaming.

A rap song could have screaming in it, but it would still be rap. It would be like if
someone said that pop, rock, and rap are all the same genre just because they all
have a guitar. Only, in this case, people are saying that metal, hardcore,
post-harcore, and deathcore are all the same genre just because they have
screaming. It's so wrong. They are totally different genres. But most people stop
listening the second they hear screaming, so how would they even know? It's
judgemental. It's wrong.

People stop listen the second they hear screaming, so they never listen long enough
to hear the obvious differences! They don't know what they're missing though.

There's no such thing as screamo. It's just not a genre. It's not.