Oh for sure this makes sense. When i buy the bundles i tend to only actually keep like 1-3 of the games and sell the rest, which usually means i spend like 2-3 bucks a bundle and wind up playing at least half the games i get so it works for me pretty great. But yeah if you're spending 12 bucks and playing just a handful of the games you buy not so much for sure, but then again most people in this forum tend to have hundreds of games they dont play anyway
Well, I think the other thing for many is - well, the price of buying the game you really want by itself (and/or version from the service you prefer, such as Steam for many) can be a little less, close to or equal, or a littler higher in the Bundle.
In which, if there's other stuff you want and do actual play in the HBC (or any other bundle, for that matter) - yeah, it'll be more worth your while to buy the bundle.
Only other time you might really do good is: say you activate a game you don't care about...but then it gets pulled from Steam (and any other service). I dunno 'bout you, but...it's always cool owning stuff that you can no longer buy and is no longer for sale anymore anywhere; especially stuff w/ licensed-stuff (licensed music, licensed cars, licensed characters, licensed IP's, etc etc).
I've been looking at Call of Chtulu (Cyanide) and Coma 2 - so, for those two alone, probably worth just grabbing the bundle, no matter what I do w/ any of the other keys (activate them, giveaway, or whatever).
Pretty much, for those two alone (Call of Chtulu which I can never spell right and Coma 2), it's tipping me to BUY.