There are multiple reasons
1. Currently, Market is FLOODED with option writers and it makes it difficult for the smart money to make money. Therefore, option premiums are managed to discourage retail investors from option writing.
2. Some big players buy option for hedging purpose. Therefore, they try to manage option premiums (using demand supply principle) to minimize their hedging cost.
3. To attract retail investors towards option buying by projecting that premium decay is just a myth and probability of losing money in option buying is low.