The fees must go up or some measure to kill spamers.
Larger blocks does not prevent spammers.....
The higher the blocksize, the more transactions can be processed and the more expensive a spam attack is per minute.
But it is all a nominal amount of money in the grand scheme of things.
Bitcoin should be secure against government attacks, let alone someone with a few grand lying around.
If it currently costs a few thousand $ to clog up the blockchain, even increasing it 20 fold wouldn't stop someone with deep pockets.
A work around needs to be found, not just a simple block size increase (though that should happen too)