I need to open with a disclaimer that I'm ignorant. I don't understand what is wrong with spam on the blockchain. The spammers are paying for it, right? I see the fight against spam as a little limiting; it's like telling a caveman not to draw on the cave walls. This is just my instinct. I know very little about the whole thing.
Discussion
It takes up space, so node runners need to buy bigger hard drives to fit the blockchain on their nodes
Storage is cheap. People were buying racks full of drives to mine stupid Chia, but few extra gigs of spam is a problem? This is exactly what I don't get. Again just a gut feeling.
Spam in OP_RETURNs can *decrease* the load on nodes, as the OP_RETURN data can be discarded ('pruned') by the nodes.
The best block, from a storage point of view, is filled with just one transaction that has a huge OP_RETURN taking up the entire megabyte.
(Even better is if the transaction takes many UTXOs as input, and has just a few outputs. But that's a slightly different issue)
Ethereum and other utility coins were invented so that people could put stuff on a blockchain that isn't Bitcoin, because Bitcoin was created for monetary purposes.
bitcoin is monetary network & I don't want to have spam on my node, having said that I am aware that we cannot completely remove spam but this does not mean that we should remove all spam filters. You have spam filter in your email but you still get spam but just because some spam finds its way to your inbox doesn't make you to remove spam filters.
this is my opinion, if you don't agree & run core, I will not attack you or support anyone attacking you. this is what makes me mad, core developers not only push their spam into bitcoin but they attack people who don't agree with them. this is unacceptable.