The opposite reason old music is so memorable. No strong central melody hook. Old systems had to rely on shitty sound chips with only a handful of sound channels, which is why all of the music is centered around one main melody, a beat, and either bass, countermelody, or a harmony or two, rather than ambiance and generic movie scores style songs that pervade the medium now. It was necessary to have music with a good hook, because the alternative was to have nothing but an unbearably boring series of deets and doots.
Movie scores usually fucking blow for general listening, because most of them are only meant to set the emotional tone and stay out of the way of everything else, rather than be enjoyable on their own. In terms of movies, John Williams is revered as God-Tier because he can make music which accomplishes both simultaneously, which for some fucking reason, almost nobody else in his medium can do. Hans Zimmer rarely does it for some reason, despite having the ability.
This is why any retard on the street can hum you a tune from Mario, and anyone with more than a passing interest in video games can hum you the main theme of Zelda. It's why everyone knows the main theme to nearly every movie John Williams worked on, but fucking nobody knows the main theme to The Emoji Movie. The problem is that the most emotion in music is attached to the main melody, which means that it's the most risky. Why take risks, when you can be as generic as possible and still get the lukewarm but overall positive reaction from normalfags who have no appreciation for the artform, but know that they felt something?
The thing these fuckers keep forgetting is that human beings attach melodies to other concepts and meanings, which makes those melodies an emotional shorthand for that concept or meaning. Just the first few notes of Wily Castle or Proto Man's whistle are infinitely more meaningful than anything in Generic Soft Piano Fantasy MCXV. That emotional attachment is so much more powerful than any generic score that it blows my mind that anyone would willingly choose to go with the generic score unless they were on an extremely tight deadline, (which most game composers are not) or they just knew they didn't have the skill to make anything better. It drives me up the fucking wall that fucking SQUARE of all companies, whose most well-loved soundtracks were made by people who get it, like Nobuo Uematsu and Yoko Shimomura, is failing on this front. A game like VII is in the same series as a game like XIII.
Of all of the Extra Credits videos which qualify them for a firing squad, their video on this topic is probably in the top 5. They explain exactly what I just did, but then immediately revert to "No, modern games are fine, games are better now because we have better technology and because they're new, even though I just completely blew that notion apart with my own argument."
Holy fuck, this topic triggers the shit out of me. Vid fucking related.