The phrase is Indonesian slang, with nggak being the casual form of tidak, meaning not. Clips built around short spoken rejections circulate widely in Indonesian meme edits, WhatsApp groups and short-form video, where a single line can stand in for a whole reaction. This one gained traction because the dislike is oddly specific to reggae, making the refusal sound funnier than a plain no. It is now reused far beyond music, as a quick way to shut down any idea the poster dislikes.