Sometimes overly-ambitious technical projects that fail still provide value indirectly.

The project is invested in to an almost absurd degree, with absurdly large goals to reinvent everything, and then collapses under its own weight.

But the knowhow and technologies developed in that project can still go on and be useful inspiration for more realistic systems later.

For example:

Microsoft's Cairo in the 90's, which gave COM, Plug-and-Play, and others.

Google Wave, which gave Operational Transform.

Google Turquoise

These kinds of high-profile failures are like a whale fall, a bonanza for scavengers.

Lots of new components to do lateral thinking with weathered technology with.