BoxOfSnoo: It's not because they're trying to track you, or measure your cholesterol level, or follow your financial transactions, or even force you to buy games from them.
It is because they want to promote Steam gaming and Steam games with it. Claiming otherwise is just naive.
What next, an EA graphics card you can configure only by using an EA Origin online account and with games you have attached to your Origin account? Does that make any sense? Is that where we should be heading, hardware devices pretty much requiring online store client accounts? That just fragments the PC hardware market and PC gaming overall.
And so does the Steam controller. Let's put it this way: would it be ok to you if you had to buy separate gamepads for your Steam, EA Origin, UPlay, Windows Store and GOG games? Five gamepads, just because each gamepad works less satisfactorily without the corresponding client?
BoxOfSnoo: Even Xpadder requires a client app to, you know, configure the controller.
(sigh) The client is not the issue here, Jeffrey. The online account is. Does XPadder require you to create yet another account online before you can configure the controller with it?
Having said that, a "client", or rather an utility, to configure your device may be needed, but should be minimalistic. I need a "client" (an offline tool actually) to configure my wireless Logitech keyboard, mouse and trackball so that the PC finds them the first time. After that I don't need to run the "client" anymore, nor do I ever have to create an online account to use that tool.
That's how it should be. If you want to add optional online features on top of it like ready-made configurations online for the device for different games, by all means do, as long as they are optional.
Also I don't quite get why you'd need to have an account to get such configurations. For what purpose? Couldn't you, like, download (or even upload) game controller configurations anonymously? How does it benefit you, the user, that it would require you to create an account first?