SirPrimalform: Right, because a bundle with 5 DRM-free games and Steam keys for 2 of those is Steam focussed. :P
The IndieGala and BeMine bundles are Steam focussed (Steam keys for nearly all the games, barely any DRM-free downloads).
Barefoot_Monkey: It caught me by surprise too. I guess it's just a slight misnomer for "bundles which have Steam keys included". Still, it's a useful category for those who happen to be looking for Steam keys.
True... I guess it's just not a very useful category for people like me who aren't interested in bundles that consist mostly or solely of Steam keys (e.g. IndieGala), but don't mind a bundle having optional Steam keys (e.g. Humble Bundle).
Since the title makes it sound like they're all the former, I'd be in danger of writing off things like the Humble Bundle (which is arguably DRM-free focussed). :P