* Fees do not prevent an attacker from spamming. A determined attacker will simply use a different client. By putting this ineffective measure in the official client, we only punish legitimate users.
Please direct me to this other client that can cause other nodes on the network
to accept and relay my fee-less spam transactions.
That is not the issue. The issue is that a determined attacker can broadcast
transactions arbitrarily fast. You are right that other nodes can choose to ignore them, but that's not the issue. And anyway, that just furthers the case for removing
fees as an anti-spam measure.