Seems like a paid alpha for a product that will be viable in 10-15 years time when ISPs (hopefully) improve their edge networks. I'm sure it will work soundly for a blessed few - whereas the rest of us on congested, inconsistently performant networks will just experience the same thing as most did with OnLive - noticably laggy, jittery gameplay. I suspect this generation's services will all fail, publicly, but provide Google, MS et al with the data they need to re-launch them when the majority of the world's infrastructure is capable of supporting streamed gaming fairly reliably.
But on a different note, just how was the conclusion that this is economically unviable reached? The traffic point is pretty moot - streaming game video is just the same as streaming Netflix, and that certainly hasn't been a problem. On the hardware front, as a cloud provider Google willl have plenty of spare compute capacity in its DCs, and Stadia will be niche enough to run lots of part-time casual gamer workloads with demand balancing while it works out how far to scale. Spare capacity is wasted capacity, so it may as well be put to some use...