As others have mentioned the main reason a product gets “killed” midway through the research phase is simply due to the money. If the research and development of the device is taking too long and upper management is not seeing the proper growth and timelines are not being met, they can begin to slowly defund the project, and focus on another product. Potentially pulling a product midway through in the planning phase could only be done by a larger corporation because they can take the hit of the potential lost money and due to them being a larger corporation they have other potential projects they could focus on. However, for a smaller company or even startup, most of the effort is focused on this one project and if the product gets “killed” its essentially the end of the comapany, or it would certainly be bleeding of money.