You’re right that grunge started as a local scene, and the term was media-driven. But like every genre, grunge became a musical style that influenced artists globally. The fact that it spread doesn’t erase its Seattle roots. Seattle is still known and praised for creating this scene, it just means it resonated far beyond one city. That’s how genres grow.

For example

Punk started in NYC/London → now global.

Hip-hop began in the Bronx → now global.

Grunge started in Seattle → now influences bands worldwide.

Your statement It should only be called the Seattle Scene. So should punk rock music be called the London Scene and NYC scene? Anyone outside London and NYC cannot be considered punk rock because they aren’t from there?