I'm tired of every time my steam disconnects for a minute, I get disconnected from SK. I don't understand why SK still needs to be in contact with Steam after I've logged in. This actually makes it more of a hindrance to be playing through Steam, I wish I made my character outside of Steam now.
If you absolutely need to be in contact with Steam, why don't you at least put a timer on it....say after being disconnected from Steam for 5 minutes before booting me from SK. Sheesh!
Functionally they don't need to, but I've always worked under the assumption that this how Steam wants to do it. They have same requirements in TF2 (last time I played anyway), where if the system is out of contact with Steamworks for extended periods, the system can't validate you as a player and kicks you off.
For games where multiplayer is optional, single player modes aren't affected by this requirement... but when your entire game is built around a centralized multiplayer client/server relationship, client integrity is your predominant concern.