Depending on your work habits, your speed or your machine it might happen that empty segments are being marked as "translated" or "checked". This kind of mistake is being discovered by QA (Empty segments). But the QA is at a very different position in the workflow.
Nevertheless it would be nice to have an option in the Preferences to avoid this (kind of "Do not allow empty segments to be confirmed" checkbox).
I know that sometimes – but only in very. very rare cases – you might want to have these segments confirmed (also as they cannot be simply locked), but in my very humble opinion the block of confirming these segments is more important (yes, and in this case no need to ask for a pop-up or dialogue box, yay!).