While I would normally totally agree that we all have a duty to save electricity, this is something special:
In Second Life Sim owners pay astronomical fees for a sim. Yes it is that much, that you can buy THREE of your own HP quadcore server blades on ebay per month from the monthly fee, you can buy more than 10 server blades from the setup-fee! Or you can rent at least 30 linux root servers from services like 'rackspace hosting' from the same monthly amount!
My **** you can buy a whole datacenter on ebay with the annual fees!!!
I think with this high (?) standards (?) and pricing, nobody consents to pay for an idling sim. And it does NOT matter whether it affects running scripts or NPCs or anything else in the sim, or not. It is just that we pay unbelievable astronomical high prices for this service so it is our god-given right to act lavish with these resources that we are paying for!
No excuse, no sympathy. NO, no no!
ETA: As far as I can remember from previous office hours (in pre-region-idling times), we were told that the processing power of an empty sim is minimal. So I don't really understand any of the lines of arguments here.