Network traffic makes sense if you consider that network traffic is active usage - and the routers, switches, infra all need power. Whereas a typical user's CPU sits idle most of the time.
You should get your money back if your sleeping laptop uses 2W. At that rate, a MacBook Pro would drain its battery in only one day. Correctly-working laptops should draw about 100-200mW and their batteries should last for a week or more.
6-10W kinda sucks for an active desktop, much less a sleeping one. My development system while in S0 currently measures 3.04W (of course, ~30W when running hard).
