True. They might not. But maybe they only want to threaten (e.g., Google Fiber) that X, Y or Z might be possible?

The other reason for such things is talent. If you want to attract top talent you have to (R&B) toys for them to play with. On the other hand, to say, "We'll never release this so let's not put any effort into it" is the road to irrelevance.

The budget for this effort vs the cost of irrelevance make such project a solid investment. Pointless in terms of product but essential to the brand.