TeMPOraL had the most plausible explanation up thread a bit - apparently it's there as a copyright claim safety-net for Wayback Machine, but making a feature that runs counter to the whole point of the site publicly available makes my head hurt.
Perhaps having a bot generate a synopsis of removed content, and showing that in its place would solve any copyright issue fairly elegantly?
Generating a synopsis might have other implications (e.g. accusations of libel if the original author considers the synopsis attributes false claims to them).
Perhaps having a bot generate a synopsis of removed content, and showing that in its place would solve any copyright issue fairly elegantly?