Okay, I have more time to go into detail about some of my thoughts.
First of all, I should say that I didn't read the linked article. Nor did I watch the Google GDC keynote. I watched this video summary of the Google GDC keynote:
Basically, my opinion is that streaming video game services are an anti-consumer, DRM-pusher's dream come true.
The player doesn't own their games (DRM)At any moment, and for any reason, the service can terminate your account and revoke your access to any and all games you've played, including the associated save data. For some people, on some games, that can amount to hundreds or even thousands of hours of progress lost.
In addition, it may not take long before license agreements expire and are not re-negotiated and you end up with a system where your favorite games suddenly disappear from the library.
Combine this with the increasingly censorious nature of Silicon Valley tech companies who will unperson (ban/deplatform) anyone they arbitrarily deem to be engaging in wrongthink, often without offering a method to work toward absolution, and... well, no one should be surprised if they suddenly lose access to some or all of their games, e.g., because they expressed the wrong opinion on Twitter, Facebook, or even "privately" in Gmail.
Monthly subscription feeAs far as I know, no pricing information was revealed, but it's hard to fathom such a service will come without a subscription fee. If there's one way that's sure to kill the enjoyment of games (at least for me) it's to require me to constantly pay for them to be able to continue to play them. To me it makes it feel more like I'm obligated to play; I feel that if I have any free time then I need to be playing the game(s) I'm subscribing to in order to get my money's worth. And if you stop paying, once again you've got nothing to show for it. I don't like the idea of renting things that I'm going to invest a significant portion of my life into, and this is essentially doing just that.
LatencyThe USA is a big country, with a lot of real estate. Yet tech giants in the USA as well as companies from other (comparatively) tiny countries seem to think that New York City or Los Angeles are accurate indicators of what's available in the rest of the USA. I'm fortunate enough to live somewhere with reliable access to broadband at semi-decent prices. But my ISP (the local cable company) still enforces a data cap. And while download speeds (150 Mbps) are nice, upload speeds (5Mbps) are comparatively slow. And I know people who live just a few miles from me whose only access to broadband is wireless or satellite with much lower speeds and much higher latency.
In short, affordable, reliable broadband speeds required for a service like this to run well are not as widely available in the USA, much less the rest of the world.
Spyware/Privacy ConcernsThis is being offered by Google. Need I say more?