CC don't seriously tell you (politely or otherwise) what to do with your window blinds do they?
I have travelled on several airlines where the cabin crew has insisted (politely but firmly, with no indication that the passenger has a choice) that the blinds be lowered - off the top of my head I can remember this happening on ANA, Ethiopian and BA in the past few months.
It doesn't bother me, because I prefer not to have a window seat, but some passengers clearly resent having to block out the view and the light.