No one is saying filters are 100% effective. People still put up walls and fences even tho you can jump over them. We should make it harder not easier for people to abuse the network

Not if enough nodes enforce a new set of rules, right? Miners can pack any valid tx into a block, but nodes are the refs enforcing the rulebook. If a majority of us agrees JPEG spam is out of bounds, we can tweak the official rules and miners have to play ball.

The miner which is doing this, risks slower block propagation through the open relay network and by that risk of an orphaned block. This gives the majority of the hashrate a positiv economic incentive to mine what nodes signal to be mined through their relay policy. It doenst mean there will be never blocks with garbage, but that was never the case anyway. Why is that point always glossed over?

It's always about incentives. Node runners are still free to determine what's get filtered. Miners are free to determine which transaction they mine. If enough node runners are fed up with a bloated mempool on their node, they should take action and this in turn will incentivize miners to consider the risk of slower block propagation. Lynn's point does raise a valid about the cost of transactions that need to disincentivize jpeg's over valid tx's. In times with low tx volumes, jpeg bloat provides extra income stream for miners. While in times of high tx volumes, jpeg bloaters will think twice if the cost of their monkey pics are worth it.