The fees must go up or some measure to kill spamers.
Larger blocks does not prevent spammers.....
The fundamental premise here (that all attacks need a response) is entirely flawed.
To accept it is to surrender completely to the will of every would-be attacker that can force a response.
If you want your TX processed swiftly, raise your fee. You can fix this yourself, it needn't be something you ask ANYONE else to handle for you.
Exchanges often have a fixed default fee that you cannot change. Implementing your suggestion would require all exchanges and Bitcoin services to update their platforms to allow customers to set their own rate of transaction fees. Ideally they should also warn if the network is under attack and suggest an appropriate fee. It would take some time to get them all to agree to update, but it's possible.