Why does everyone hate Johnny Test?
Well I for one loved that show when I was younger, now my mom thought the mom was going over board with her feat of germs and thought the dad was annoying, but me and my siblings loved the show!
It's impossible for "everyone" to hate the show. You haven't asked everyone their opinion & everyone hasn't voiced their opinion. I personally have never seen it & I'm part of "everyone", so your question cannot be realistically answered.