As a console gamer, I'm interested in a Steam machine not for the latest games, but rather to run older games on much nicer settings with a console-like atmosphere.
For example I'd love to grab one of these with a steam controller and finally play games like Morrowind GOTY at 1080p. The only console version of the game which exists maxes out at a miserable 480p on the OG Xbox.
I think console gamers who jump in on this will really get enjoyment by finally being able to run their favorite classic games from the past 2 gens at their HDTV's native resolution with all the bells and whistles at 60fps. That's sort of the true allure to these low end steam machines in my humble opinion.
It's a really interesting proposition for someone coming from consoles.
I've been using a homemade steam machine lately and the primary benefits coming from console are in order:
1: Genres available that are not on console. Especially strategy/building and rpg.
2: Legacy gaming and backwards compatibility heaven. Especially when you go beyond steam.
3: Multiple stores to buy those games, leading to great prices.
4: Cross platform playing. Two of us have steam machines, and we can call up anyone with windows or mac to join for some tf2 or whatever. Most the time we play, it's irl friends with two steamos machines, two windows machines, and a mac.
5: My purchases are tied to my account and will play on any pc hardware.
6: I define my own upgrade cycle.
7: It doubles as a fast computer when I need it to. My steam machine runs the shit out of blender, while my trusty macbook is just serviceable in comparison.
8: All external usb accessories just plug in and work, which has already saved me money.
I could probably go on. But suffice to say I like the experience so far.