I am much the same with lyrics, typically. The voice is just another instrument. This and my enjoyment of a wide variety of music, including a lot of traditional stuff from around the world, has been of benefit to me when I have traveled, since it allowed me to enjoy stuff that was around me. Sometimes the local stuff was not appealing to others who were with me, and my appreciation seemed to only reinforce their view of my eccentricity. I just like what I like, and I don't care much what others think of me or my tastes. I do try to tone it down in certain places, or around certain people (children, for example).
Edit: The above isn't limited to music so "stuff" can include many things. Another great example is food. I love food.
I have never given NSBM a listen, but I have heard others say things along the lines of what you did. I suppose it isn't a bad thing to stop listening to music that you like the sound of but disagree with the content of. There are some who think that entertainment can be used to influence beliefs and such.