I agree that the transaction is perfectly valid.  However, valid or not, until that transaction is recorded and confirmed in the public ledger, the transfer of coin is not legitimized.  An empty block certainly helps to ensure that malicious activity becomes that much harder to perpetrate on the previous blocks, but it does nothing for all of those transactions out there waiting to be added to the chain.  Now, if there simply are no transactions to be included, then by all means, add empty blocks.

Not sure I follow here... I've added an empty block to the chain (well, there's at least 1 transaction because of the generated coins).  That block has no other transaction.  It does, however, know its parent.  Are you stating that because I know my lineage until genesis, that's equivalent to having all transactions in every block?  I'd argue that if this were the case, then every block would be larger than it's predecessor.  Genesis would be size (n), block 1 would be (n + m), block 2 would be (n + m + x) and so on... obviously that's not true.  I'll agree that every block has knowledge of its own transactions and a way to get to all previous transactions, but not that every block has every transaction .