Emo is how I feel when I go to take a shit and one of my roommates is in the shower.
God I nearly fell off my chair when I read that.
Anyways, old emo is one of a long line of musical sub-genres which I am merely apathetic towards.
Modern emo, de-pop, emocore or whatever you want to call it is bad for every reason music can be: Awful lyrics and no musical ability.
Being a fan of metal I want to punch the store manager in the face whenever I see 'My Chemical Romance' or 'Panic! At the Disco' in the metal section. They are in no metal, in many ways they are barely music. Any genre where singers cry on stage after nearly every song (Brand New) or sings in an awful voice but becomes famous worldwide (Fall Out Boy) deserve binning.
But again I could say this about a whole list of other genres: nu-metal, rapcore, Jay Z/50 cent etc. Style hip-hop/rap/urban, Artic Monkeys style 'indie' I could go on.
In the end there is always going to be music which people think sucks. It's just a lot worse when that of sucky music either 'inspires' (Im using that word in the loosest way possible) people to commit violence against themselves or others.