I imagine that extra power consumption has to be less than the combination of non idle HDDs and all of the other infrastructure at backblaze, no? And they're still going to be idle most of the time.

And there's the added likelihood that people providing hdd space on filecoin are not going to even measure the impact of extra power consumption, they're just going to notice the revenue. (Not that this is a good thing, if someone was losing money, they should know)