It's not so.
What it will have (if you've bought GalCiv II online) is product activation. This will be handled by Stardock Central automatically in the background during installation/updates. You will not need to be online to play GalCiv II, however.
If it were Steam, you'd have to use SDC to launch the game. If it were Steam you'd always get verified each time you play or wait for several minutes while it checked to see if you had an Internet connection. If it were Steam you wouldn't be able to back your game up onto a CD. Shall I go on?
There are many great features available to you once you register, including:
Sign in or Create Account