bit_user :
I'm struggling to follow your line of reasoning, here. Are you saying it's okay for Apple to discriminate against Valve, because neither are really such big players and Valve doesn't really have that much at stake, anyhow?
I'm responding to the suggestion that Valve somehow needs to have their app on iOS, when it's really probably not that important to them in the grand scheme of things. Will the lack of their PC game streaming app on iOS significantly hurt them? Probably not, as this is more of a side feature for Steam, and something that is still available for most mobile devices and smart TVs.
bit_user :
Newsflash: Valve doesn't own a platform! Not a mobile OS, not a console (not since their abortive Steam Machines effort fizzled), and not a desktop OS. If they had a major platform and distribution network, now there'd be some level of parity.
I'm referring to the Steam software distribution platform, rather than an OS or hardware platform. Imagine a company wanting Steam to distribute their own storefront for buying PC games, for example. Steam isn't going to distribute software that is directly competing with their own storefront, through their storefront. Steam Mobile allows users to purchase games through Apple's devices, however, that's a bit different, in that the games are not designed to run on the same device, and the functionality is only streamlining something that can already be done through a browser, so by itself, it's not really competing with the App Store. This new functionality effectively allows these games to be played on the same device though, which takes things to another level. Rather than someone buying a game from the app store to play on their device at home, they might purchase something from the Steam store instead, and in some cases, games are even available for both.
About the only difference here between the App Store and Steam is that Apple controls the OS as well. So, where you might be able to go elsewhere to download and install something like EA's Origin or Battle.net or GOG Galaxy on a PC, you can't really do that on iOS. However, it can't really be argued that Apple holds some monopoly over smartphones, because again, they only make up a relatively small portion of mobile devices sold. The majority of such devices run Android, an OS that does allow users to install applications from elsewhere, at least after toggling a switch in the settings. If people don't want to be limited by such strict controls over what they can do with their devices, then there are plenty of less-restrictive products for them to choose from.
And while I'm not much of a fan of restrictive hardware platforms that limit what can be installed on them, where does one draw the line about what restrictions a company can place on what's allowed on their devices? Should Playstation be required to let Microsoft sell games on their consoles with its own storefront? If someone really didn't want such limitations on a console, then they might be better off gaming on a PC instead. Likewise, the same could be said for Apple devices, even if Android isn't quite as open as PCs are.