Refrencing to this https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.9.0.md

OP_RETURN and data in the block chain

On OP_RETURN: There was been some confusion and misunderstanding in the community, regarding the OP_RETURN feature in 0.9 and data in the blockchain. This change is not an endorsement of storing data in the blockchain. The OP_RETURN change creates a provably-prunable output, to avoid data storage schemes -- some of which were already deployed -- that were storing arbitrary data such as images as forever-unspendable TX outputs, bloating bitcoin's UTXO database.

Storing arbitrary data in the blockchain is still a bad idea; it is less costly and far more efficient to store non-currency data elsewhere.