I'm not 100% sure why they have a "repo" for an "installer". It sort of rather defeats the purpose. If they're going to do that, just put the client in a DEB and put that in the repo. At this point I see no reason in adding the repo to apt. Either way, it'll get sorted, Steam for Linux is already quite great. Still can't get over that TF2 runs better in a window in Linux than I've ever had it run in Windows.
Steam has a package so dependancies can be satisfied easily without resorting to "install xyz beforehand", and it runs an installer into your home folder because the user has to be able to modify the games directory for many, many games on steam, because stuff like configuration, custom maps, custom models etc, is stored alongside everything else. Also steam has diff based patching (which requires accress from whoeve…
This isn't even true. The deb has dependencies just like any other DEB you'd get through apt-get. That's... kinda the point of package management...