I was thinking that an ideal way to eliminate spam would be for the miners/nodes to agree to not process txs that use a fee lower than 10 cents. We'd probably go down to 200-600kb blocks right away (depending the load) with plenty of room to spare - and probably everything would go in in the first block. But having prices in USD doesn't work in terms of code (which deals with BTC fractions).
It's all price controls and cartels with you, isn't it?
It's about game theory and economic disincentives in order to defend against system(+atic) abuse. If you read the Ethereum link provided above, you'll see some subtle criticism against bitcoin for leaving the abuse disincentives (fees) to be ...determined by the free market. Litecoin also didn't leave the abuse prevention fees to be determined by the free market: The imposed a fee patch. Monero also saw first hand the effects of a bloat attack and raised fees.
As you can understand this is not about me.
If
you made a coin tomorrow, and someone started killing it for the lolz, you'd patch it up with some kind of fee increase / block restriction. Common sense.