If the current fee rate is 10 s/b, a spammer isn't gonna pay 30 s/b to mara. They will just pay 11 and broadcast to the libre relays. The more of a gap there is, the more incentives for miners to defect and mine these span TXs. It's market incentives all the way down.
Discussion
Which is why relaying spam makes sense
What I'm saying is, let the market handle it and cast your vote based on what you wish to see on the chain. Don't make up complicated hypotheticals to explicitly do something against your values for the greater good.
And what Iām saying is that doing so causes the problem that nobody wants.