On the validity of "comparing" DT to NW

It's kind of like justifying why I prefer to listen to Chopin over Bach. They're composers of completely different styles, in different forms, for different instruments, for different reasons. I like some music from their respective periods (Scarlatti and Schubert for example), and dislike some from the same (e.g. Handel, Wagner); so it's not a matter of liking one period of Classical music more than another*.

Yet it is completely valid to say that "I like Chopin more than Bach for the following reasons: ..."

...but not the same for contemporary bands?


*Again, such labels of periods are arbitrary, and therefore there is *still* no such thing as the "Finnish national style of metal." Thank you.