A simple way to analyze this is to look at extremes.
If there was a 1 second Power Down time exchanges would probably power everything up.
But if there was a 10 year Power Down time, they'd probably Power Up much less. So I don't think it is about the Power Down time not influencing them from Powering up but by how much.
P.S. I also didn't advocate for increasing the Power Down time but I want it to stay at 13 weeks.