Some interesting thoughts. I've generally been in favor of a much shorter power down time (whatever is needed to avoid exploits which seems to be something like 5 days), but there isn't consensus for it. If we look at similar but more successful chains like EOS, they have (I think) two day power down and they don't appear to suffer for it any significant way.
Perhaps with continued discussion and comments such as yours more consensus can be built.
RE: Open Letter to all Steemians - Hardfork 21: Culture Change