I don't think it's "hate" at all...(man, is that word overdone and incorrectly used these days!)...and even though I won't use a controller made by anyone as a hi-res mouse and nice keyboard do it for me, the lack of buttons seems troubling from a design standpoint. With somewhat slick surfaces, say this controller's touchscreen, you more or less have to be looking at the thing to place your finger correctly--which means what? It means eyes off the game. With buttons you have a tactile feedback that you can memorize without looking at the controller--kind of like Braille works--their hands memorize the controller via the buttons and other protuberances by tactile feel. With smooth and slick control surfaces, even people used to the controller are still going to miss the right touch point probably 20% of the time--which means eyes off the game, again. This looks like the "ideal" controller designed by someone like me who uses mouse and keyboard and plays the kinds of games in which it doesn't matter if you take your eyes off the game for a few seconds every so often...I'm not surprised it doesn't appeal to people who game exclusively with controllers.
Well they stated the touchscreen in the middle would bring up a window on your TV screen with a mirror of what's on it - so you don't have to take your eyes off the screen. No doubt that could be disabled as well but wouldn't be surprised if it works similar to how big Xbox button works in middle of xbox controller except the steam controller's touchscreen brings up the steam overlay or something.. Or the Big Picture version of steam overlay.
As for the tactile aspects that's definitely a high priority having read through a bunch of commentary from game developers valve invited to test and give feedback. For example a lot of them requested that the control surfaces be given slight dimples across them (aka what everyone is thinks is the trackpads). The haptic feedback also aids in letting you know where your thumb is within the control surface relative to the middle. And when your thumb approaches the outer edges that's also apparent. And then there's audio feedback cues like slight 'clicks' that tell your brain how fast you move across or swipe the control surface by increasing in frequency relative to speed.
Suffice to say every major game developer and scads of playtesters will have signed off on this controller before Valve would consider releasing it, still a lot subject to change.
As for the knee jerk "it doesn't appeal to me" coming from console players before theyve tried it, well who knows, maybe the idea of admitting something might work better than their beloved status quo analog sticks is a thought too scary to bare.