Why Thaipusam Largely celebrated in Malaysia?

Hellow ... I'm back. Drove back to Kuantan on Thurdays nite, came back on Sunday to avoid congestion on Monday and Tuesday along Batu Caves road during Thaipusam.

I don't know much about Thaipusam, I had a Indian friend from Bangalore who doesn't celebrate Thaipusam. According to her, Thaipusam is a Hindu festival celebrated only by Tamil community.

"The Tamil people are a South Asian community living mostly in Tamil Nadu state and neighbouring areas in south-eastern India, in the north and east of Sri Lanka , in Malaysia, Singapore and etc."

India has 65millions Tamil devotees, and Malaysia has 2millions, yet the largest Thaipusam celebrations take place in Batu Caves (Malaysia). National Geographic also always refer to Malaysia when it come to Thaipusam celebration..... How come ha?