Because Gryffindors are big-ego’d, small-brained, conceited, numbskulled bullies who think they’re worth more than everybody around them!
And Slytherins don’t blubber.
Being, I suspect, a fiery light of stupidity for all mankind, you probably didn’t notice anything less than the flashiest of heroics going on in the noblest house. So I guess you really can’t help your truly astounding ignorance.
~ Draco Lucius Malfoy