Sapphire_-_boss.mp4
[Hide] (6.8MB, 1280x720, 02:02) >>260353
>“Rockin” means “good” in this context.
In OP's context it actually seems to mean a bunch of bland pop music with singing. I normally like video game music for precisely the opposite reason: wailing narcissists shut the fuck up and we get to rock out to the actual instrumentation.
Anyway to actually answer OP's question assuming they're describing a genuine trend that's occurring: as budgets get ever more bloated video games (including their musical choices) are evolving towards the same inoffensive crowd-pleasing cinematic trends as you see in the theaters. Grand orchestral composition is probably one of the least offensive types of musical genres.
Although if we are honest with ourselves, rock probably had a widespread popular position in Japan during the late 80s and early '90s. One of the first musical genres Japanese games really leaned heavily into as PCM technology progressed allowing for more realistic sampling in the late '80s and '90s was heavy metal and blaring electric guitars.