I don't think gaming systems and Roku as entries to streaming entertainment are great long-term, mass-market options. They are/were good for early adopters or the more tech-oriented. But for the larger markets, Chromecast, Apple TV, the new Amazon service, and smart TVs is where the market is evolving.
You don't think that the Xbox 360 (with 79.4 million in sales[1]) are a better long term, mass market option than the Apple TV (with 13 million[2])?
Games consoles are not very tech-oriented. The Roku is every bit as tech-oriented as the Apple TV (they're basically the same product by different companies).
I would say the percentage is higher than you think. So much that the Xbox One seems to be designed more like an entertainment system than a gaming console.
I don't game much but I use my Xbox 360 as a glorified streaming device. WMC, Xfinity and Amazon Prime all of them are convenient on 360 especially when compared to Comcast's clunky set top box interface. Ohh did you know Comcast allows me to stream full HD for free on the Xfinity app whereas to do it on their Set Top Box, not only do I have to get a new one, I would have to pay $5 extra per month.
I think you're off base. Roku is a very mature product. Amazon might be able to beat it with marketing, but one could argue that Chromecast, Apple TV and Amazon have to catch up with Roku.
You're absolutely right. Roku has been around longer and is more fully featured than many of its competitors, but that's not going to matter in the long-run.
Google, Apple, and Amazon all have substantially more brand recognition and marketing power than Roku. Additionally, those three companies are also building upon their existing businesses to drive their TV devices and strategy. Smart TVs are also going to cut back on the number of people buying these types of devices.
Roku is a fine option, but I don't see it being a big player a few years from now. I may be wrong, but I think they'll ultimately end up serving a niche market.
The Amazon Prime, Netflix apps are front-and-center on the Xbox and PS3 console dashboards. One click install, enter username / password, and you have a very easy to use navigation / search for instantly streaming anything. If you own one of these devices (a lot of people do), it is a pretty easy experience.
The problem I have with devices from Apple, Google, Amazon are that they limit them to make their own content front and center, and often they won't even allow sources outside their own. With a console, I can stream from Hulu, AMZN, Netflix, or a PC in the office. Plus if you add a DLNA server like http://playon.tv, you add hundreds of other sources.
With the Amazon Instant Video app on an iPhone/iPad you can use Airplay to stream to an AppleTV. I've never used it but do this a lot with BBC iPlayer which works really well for me.