So. People dont uderstand, why they're not just dubing the original for a wide re-release.
To give you the only reason necessary: Money!
Sure they would make a pile of money with a tiny investment. But who would win that way? So instead, they do the usual thing, call for a remake, invest millions, and bet on multiplying that amount with a country wide and international remake-release. It doesn't matter if the film is shit or not. It sells on the good name "The Raid" alone. And if the movie IS bad, they cann blame the original for not having much substance and wash their hands in all the money they made.
They can overinflate budgets, place products and film in locations like the ihop. Everyone wins! (except for the audience, but who cares about them? They already paid)