Wow, lots of FUD going on. Here we go.
First, it's absolutely inexcusable that this doesn't have HDMI 2.0. Inexcusable. Tons of TVs, AVRs, etc have HDMI 2.0 now. We've waited (what has it been, three years?) for the Apple TV to be updated and they can't even offer the latest in HDMI?
Second, 4K is neither expensive nor niche. Have people been to a Best Buy or such store recently? That's all you find are 4K TVs. Netflix offers 4K content, so do other services. I just bought a Samsung JU7100 and I've been watching House of Cards (Netflix). It's glorious. And so is 1080p content. I'd rather watch the content through an Apple TV, though.
Third, bandwidth is not a real limitation, not in 2015. I'm paying around $60 a month for 50Mbps. Netflix recommends 25Mbps for 4K. Getting a 25Mbps service is not exactly a hardship.
Bottom line is, there is no excuse *not* to offer HDMI 2.0. I'm putting my money back in my wallet. Disappointing is an understatement.