Periyar was fooling the masses at a time when media Technology was just started growing in India and any freak statement made raised many eyebrows amongst the illeterate masses, there was no one equipped with a strong media medium in order to counter attack his ideology.
He was criticising hinduism because Brhamins were involved, He would never crticise any other religion.
Personally all these people were man in black. Speaking one thing in public and practising one their private life.