Blame the "Valley of Death":
[A]ll innovation begins with basic research, which aims to increase understanding and is undertaken out of curiosity rather than a specific commercial application. While basic research doesn’t generate revenue on its own, it is typically well funded by universities looking to advance knowledge and government initiatives which recognize its vital role in advancing technology. Research only begins to turn profitable on its own during commercialization, when new discoveries become products and can be monetized. Between these stages, however, there is a point where government funding tapers off but risk remains too high and rewards too obscure for private funding to kick in.
While various iterations of this progression have been proposed from different perspectives, this point in research is considered the "Valley of Death" because so many potential innovations fail here, no longer cutting edge enough for university and government support but not yet sufficiently viable for profit-maximizing corporations. In many ways, this is where robotics is floundering… [T]he only way to develop robots that are functional and cost effective is to keep developing ones that aren’t, which government, academia, and industry are rarely willing to fund.
(Video from a collection of "21 signs we should give up on robots")