I would accept the argument that elliptic curve multiplication could be considered a complex process, but again, that doesn't really factor in here. The reason we don't have public key collisions is because we don't have private key collisions. The reason we don't have private key collisions is as simple as because we have almost 2256 private keys to choose from, which is an unfathomably large number.
Oh, well, that explains it! I finally realized that I've been looking at this the wrong way.
I concentrated on the fact that we cannot have public key collisions, that is, that two different private keys result in the same public key. Your argument is far more logical.