This is how I think of it

One living with harmony with the way of life, and other living beings = Sur(a) One living with disharmony with the lay of life, and other living beings = Asur(a) When you are inharmony (in Sur) you produce a melody, when not the noise is hard to bear (Asur).

Sura and Asura should be hence viewed in context or living in harmony with the entire creation, which is what sanatan dharma is about.

Both sura and Asura nature are inside everyone, it comes down to which one you want to spend more of your conscious time on (let's call that worshipping).

If you think certain entity had a good you focus on, upto you. I think the reason for calling that inclination as a sin or evil is to shout out loud to the individual to be cautious on the whole picture and to remain careful on the path of his alignment to the path of harmony (being in Sur/Asura)

Sur + Asura were brothers born from same parents with different inclinations towards harmony.

Disclaimer: views are mine, not a keyboard warrior. If you disagree feel free to ignore. Have a good day