flanner: rentware, client.. my main reasons are the same. philosophy of steam is highly unsympathetic for me. even for drm free humble bundle games u need steam account so im not intersted in hb either... and somes else.
mindblast: No you don't, you can download them from Humble Bundle site. But then again, you need an web browser and an operating system, so you are chained to software too. So, nothing it's as "DRM-free" as you think. Not to mention that most games are chained of Windows, Linux or Mac these days. Chains over chains.
Mancala seems like a good alternative, but graphics aren't so great, and you are still chained of an board/some holes and some stones. Oppression everywhere.
Ah, but there is a difference here. An operating system is just that, a system on which you operate, i.e. the machine will not function without it. And a browser is also while not necessary, recommended otherwise the internet is inaccesible. However that being said, what version or producer of the two categories you use is entirely up to you, if you don't like IE (or have any sense) then you could use any of the many browsers available, if you don't like Windows, use Linux or something else. With Steam, there is no "need" for it. People have been playing games on computers for decades before Clients were invented. Its is an additional, unnecessary, layer to chain people in for the purposes of DRM and advertising. If I don't like my browser, I remove it, I can still access the internet and try other browsers, the same cannot be said for Steam (or any other client based system, battle.net, Origin etc.). As for humble, afraid I don't trust them so avoid the site completely, their take on DRM free is, to say the least, broad.