>If the feature worked over Wifi AND 3G/4G it would be EXACTLY THE SAME
No it wouldn't. Having a protocol work over wifi is remarkably easier than having it work over 3G. The latter introduces clustering and latencies that you just don't have on any normal wifi. It's just as easy to assume that it is a bandwidth pig and is heavily susceptible to latency issues, which is why it is thus far limited to wifi.
Of course everyone else immediately started by making a solution work on 3G (and even edge), with wifi being a "nice to have extras" platform.
>I don't know what Gruber would say, but I can take a stab at it. I'd bet it would be along the lines of
When has Gruber ever said that? When the Android phones had dramatically better resolutions than the now almost intolerable iPhone 3GS and before, did Gruber ever commend that? In fact I believe the only time it even started to come up was when the iPhone 4 was an open secret and he knew it offered the new benchmark resolution, so suddenly competitive resolutions became a conversation point, but only from a "they're behind what is coming" angle.
How about Android notifications -- Gruber has defensively pushed back against the reality that Android has a dramatically better notification system. Yet, good for a laugh, he recently gushed that a notification expert from Palm (he was doing the "See Android was just a copy cat anyways" thing) was moving to Apple, clearly implying "So soon it'll get a better notification system than the notification system that was a non-issue just yesterday".
Gruber, to me, is like Republican talking heads of the worst kind. He filters information to see the world exactly the way he wants to see it to serve his agenda, which is to pimp Apple.