That's what they did after it was clear it was done as a piece of consumer hardware.
It's easy to forget how hard Google pushed Glass to consumers. They parachuted people out of a helicopter onto the roof of the Moscone Center wearing them. They invested a vast amount of money building out massive floating barges to use as showrooms, which they quietly mothballed and sold. They allowed Robert Scoble to take a picture of himself in the shower with one (some might say this was the worst crime of all).
If Google wanted to "just put it out in the world" they wouldn't have invested so much money in their consumer push. Now that I think about it, that Google I/O in 2012 was a bit of a disaster all around for consumer hardware, because it had both the Glass and the Nexus Q. At least Glass actually shipped.
Promoting it to a room full of developers is not a "big push to consumers".
Robert Scoble is not really a consumer tech reporter either. He's more like a futurist. Most of the things he likes to talk about are things you can't buy.
Maybe because you got marketed to you are thinking it was consumer marketing, but consider that you were being marketed to as a developer not a consumer.
"If you followed the news at the time there was a ton of coverage in mainstream media with bold claims about how society was going to be transformed" You cannot control what the media decides to hype their purposes. It was not as if Google itself made those same claims - that wouldn't be confirmation that the goal of the product was to transform the lives of every consumer. If they were throwing a bunch of ideas around to see what sticks that is a far cry from a purportedly failed "massive consumer push"
They were marketing to developers, but they were marketing it as something that would be useful for consumer applications. They've admitted that that was a mistake, at least in the state Glass was in when it was introduced.
The king of successful consumer products, Apple, doesn't ship out public prototypes to developers to figure out what it can do. it's a terrible strategy for launching a consumer product and one reason Google sucks at consumer products.
"We have this cool thing, but we're not sure were it's most applicable. Lets just put it out in the world and see what people do with it!"
Which is what they did. The data they gained from that experiment no doubt led to this.