Think of the investments in Loon, Taara, SpaceX and Google Fiber as part of a larger strategy to bring internet access with decent bandwidth to a larger number of humans. Some investments will not pan out, others will bear fruit.

They invested in multiple potential paths to a global internet. It's not surprising that they'd drop the investments that aren't as promising as the investments that are showing significant promise.

It's like saying I applied to multiple colleges, and because I only accepted one application, that the other applications were a failure. But, no, it could just mean that I preferred to go to the college that I accepted, but the others were a hedge against that path not working out.