I think it’s disingenuous to say that this will allow smut in the blockchain when 1) it’s already there and 2) currently possible to put more in there.
If op return had a consensus limit, I might be opposed to the idea of increasing it. But it doesn’t have a consensus limit (other than the block size). Node software just has policies about what size of an op return to relay. And any node software or fork can choose that limit. Once any miner puts it in a block, all nodes have it.
So no, I’m not worried about what was always possible and happening anyway. That is one of the downsides of it being an open, permissionless, decentralized ledger.