At the same time we must make sure that measures to counter spam doesn't get in the way of other users. An open distributed decentralized ledger without spam or other unsavory things is a dead ledger.
The willingness of people to save money by doing something in a more economical way can never die .
Even at a theoretical 1$ per tx (which would need BTC to be at 8000$ - 16.000$), that 1$ in fees is quite smaller compared to bank wire fees of tens of dollars / western union fees and still cheaper than paypal payments above 20-30$ (because paypal goes with a fixed fee PLUS a 2-3% of the sale).
Even at 1$ fees it is still more profitable to use BTC than legacy systems for hundreds of transactions per second that are currently conducted and pay A LOT more. At that point you've indirectly evicted cheap spam (no "banning") AND you are also useful to everyday people who are saving money thanks to BTC.
He set the block size limit to orders of magnitude larger than the then average block size.
He just gave attackers 1mb room to play with. To make extrapolations of use in 2010 compared to max block size (and perhaps imply that we should make like 50-100x larger blocks than what we need) is ...well.