I don't like devices that sip on power when I'm not home, or asleep. It makes no sense at all. It's not like fetching emails involves connecting to a landline, ring up a dialing device, get... The mac boots faster than my ass gets in the chair. Stuff loads instantly. I turn off the whole desk at the wall at bed time, so all the "mood lights" go off as well. Simple, safe.

I get the convenience of always on, it's just not my jam.