These bands are the bane of metal because they are bad, first of all. They make bad music. I am a bit surprised at Liturgy. Do you like death and black metal in general? I would suppose so, but no harm asking after that exchange. No malicious intent, I dont intend to argue anything, but I am interested in the rest of your metal interests. Also, you personally categorizing these bands as non-metal doesnt mean that they arent generally perceived as metal bands. They contribute to an undesired image of the music and in general make the world a worse place by releasing the stuff of landfills.
Edit: Would you wear a Liturgy t-shirt???