Actually, it's true, JAKIM has no power to enforce a lot of things. They are the central body where people "refer to for coordinating and managing anything about Islam in Malaysia".

So when people ask, "can a Muslim celebrate Ponggal?" for example, they will do some reading and meeting and come up with a unified statement: "No you can't".

But can they enforce it? NO. Can they sue somebody who celebrated it? NO. Can they instruct other bodies or authorities to adopt their stand? NO.

However, if any authoritative body decide to adopt it, then it can be enforced. So I think in the issue of Ponggal celebration, it's on KPM.