I see that alot of people don't like steam, so they install it in a different way
My question is, does that do anything better than just installing via steam?

It's just quicker to install than downloading the whole game from Steam.

are you sayingi don't need steam to play it if I have a physical copy?

They don't gain any benefit. Instead they won't get updates/patches (unless they use Steam again). Also I'm not sure how they'll distribute the mod tools. Having them in Steam's "Tools" section sounds reasonable and would be something I'd prefer.

No, all PC copies use Steam as their DRM. The only difference between a retail copy and the online purchase is (obviously) the retail disc, its box and manual. You enter your CD-Key and it will be bound to your Steam account the same way as a online purchase would do. There's just the added benefit you're able to install your language version of the game with (almost) no downloads required (as most files are on the disc).