I think the one week power down period has a value from a long-term investment prospect.
In another life I did insolvency counselling with clients dealing with financial issues. One of the tongue in cheek suggestions I used to make to clients when they got a credit card back in orderto rebuild their credit was to place the card in a bowl of water and place it in the freezer. When they wanted to spend using the card they would then have to wait for it to thaw which would give them time to reconsider the necessity of the expenditure.
The one week power down provides that cooling off period to think about the withdrawal.
As for changing the period to fully power down, it became clear that for investors who wanted or might want to draw down their investment, two years was too long to tie their money down. Thirteen weeks was a more workable commitment.
Least from the discussions I've seen, that is my take.