almacg

I didn't say atonality wasn't valid!
To me personally dissonance followed by resolution makes much more sense. Life is all about taking the bad in order to appreciate the good even more. (But that's just a stupid analogy!)
Well despite what you have said, Mars the Bringer of War could easily be described as bizarre, and when I first listened to it aged 4, I loved it. I wasn't even building towards it, my favourite music was Dire Straights for some reason...! In fact, I loved many classical works, and still do and I know that by the age of 4 I would not have appreciated atonality. I think you're right in implying that a person's taste is heavily related to their musical surroundings, but your first musical experiences can shape your entire future musical appreciation.

Free dissonance to me is a hard thing to enjoy. I am not completely blind to it, but at the end of the day western culture has revolved around the melody. I don't think this will ever change, it is embedded in our heritage and I personally don't want this to change.
As an example of the importance of the melody. Take a chord of F major with a base note of Csharp. To the average person who can't see the melodic possiblities or the possible harmonic progressions, it will probably sound quite bad. Stick a good melody over the top and bang, they will suddenly find the chord completely acceptable to listen to. It's a pyschological thing, I don't fully understand it, but to me this is the reason why harmonic complexity has to be controlled by a melody, or some kind of controlled harmonic progression, perhaps ultimately leading to a resolution or semi-resolution.

Your AMD analogy doesn't work tbh. New technology leaves old technology reduntant, but Shostakovich's 5th symphony doesn't make his 4th one less valid!