You do realize that you only need the disc for launching the game, right? Once it's launched you can take it out. To play together on a LAN, simply start up one copy with the disc, transfer the disc to the other computer, and start up the other copy!
By the way, the best way to prevent losing discs is to have a dedicated place for putting your game CDs. An ounce of organization is better than a pound of steam.
I don't lose my Game CDs and store them all in a box. It might only take two minutes to get a game that's in there *really* deep - but I'd still prefer to be able to play a game without searching for it physically. Call it lazy, whatever you want, but unlike going to the bathroom or eating, physically searching for the copy of a game is not necessary. There is an easy way to avoid it and for most people, it doesn't cost much.
I certainly do have to agree that there should be the possiblity to be able to so, f you wish, but refraining from BUYING the game is a bit too harsh, don't you think? You have concerns about your personal security because of what might be (and probably are) legitimate reasons, which is fine. You might even deem it unfair to pay for content you will never ever use, which is fine. In fact, I somewhat agree with you there because we have a similiar problem over here in Austria concerning taxes for public broadcast, which, as you might have guessed, sub-par but money-comsuming as hell.
Anyway, for the majority of gamers, steam is not - or at least does not seem as if it were, looking at those votes - an issue. It allows those who like MP to enjoy games in a cheat-free environment with features that most certainly are interesting and make competitive gaming somewhat more fun. While you as a Single Player won't need 99% of those features, achievments, whatever, they won't harm you either, unless - of course - you have general issues with steam.
Once you have passed the barrier of being so anti-steam, it's features are on the pro side, no matter how you look at it.
Also, having to have an internet connection running every few weeks, is something the huge majority of citizens of the western hemisphere can achieve. You can't tell me otherwise.
Besides, if you want to own the game physically, which I also do, what prevents you from buying a physical copy of it at your VG store next door?
BTW: Starting the game and handing over the CD to every other player at a LAN is pretty annoying...