Agreed 110%! And stop using quotes from 70s grindhouse type films or anti-Mary jane 40s schlock too!
I've been writing lyrics for my new project and am trying to avoid the 'witches at black masses' and 'yay satan' themes. Not due to any religious conviction (I am atheist) but since these themes are played the (copulation) out. And I find them boring. So instead I'm mining the other classic 'metal' themes like history, mythology, and science fiction.
We are also trying to add other elements musically, I've added psych-rock type passages, and both the guitarist and I are big 'classic metal' fans (Maiden, Priest, etc.) so trying to toss some things in that camp in there too.
And all three of us were raised on classic rock especially the "without a net" approach of say Cream, Zeppelin or Moon-era Who. So some room to improvise and let things breathe is vital. I get bored playing things 100% the same all the time. Live music should be a bit 'dangerous'.
But all metal subgenres are plagued by scores of bands that may be great in their chops/writing, but aren't pushing boundaries. I'm not necessarily saying there is something wrong with that, but if I'm creating music, I need to feel like I'm adding something to the mix, otherwise, why do something musically that other bands probably did earlier and better than you did?