I have a feeling the reason more folks shut their whole computer down in windows is because sleep / resume is "untrustworthy". I've tried using sleep/resume over multiple windows laptops , and half the time it either didn't turn the display on, or worse, the wifi wouldn't enable which caused me to reboot anyways.
I haven't had the same problems since I switched to mac, aside from occasionally having the screen not come up immediately. This lets me run many things and not feel fearful about it all getting lost when I resume.
* that said, I did watch a non-techie guy always shut down his imac when he didn't use it, seemed awkward to me but eh.