Per the legislation, you can or could receive the second draw at any time you spent or had a plan to properly spend the balance of your first-draw, but SBA seems to have drawn up different interpretations in their interim rule by requiring the first draw to be spent first, and banks seem to have taken wildly different approaches on accepting second draw applications.  

I’m guessing the banking sector figured out that the snoozers on the first draw lost out on large revenues and want to lock in a ready queue of revenue.