Honestly I don't even understand why a no transaction block should be allowed in the first place. It has no purpose on the block chain since it isn't recording any transactions.
Prohibiting empty blocks is worse than pointless. If empty blocks were prohibited, fake transactions would be created and permanently bloat the blockchain to get around the limitation.
Each block, empty or not, increases the security of every previous transaction. Sounds like a good thing to me, don't you think?