CEOs and/or senior leaders get ideas stuck in their head and it becomes apparent that no amount of analysis is going to change it. Then the product/expense is more of a “we’re doing this, how do I do it the least risky/least expensive way.”
This isn’t just products. I’ve seen examples at prior companies I worked for. It’s for getting that additional jet (we got a 3rd jet, all calcs and opinions was definitely unnecessary and barely used) or putting in this additional massive plant in a non-union state to brag about how state of the art/no risk from unions we were (plant never hit anywhere near capacity just like prior analysis showed, waste of money and eventually sold at a loss.) That said, there are lots of examples where projects and products did work where analysis failed them.
This is where CEOs can steamroll their boards, especially when they are also the Chairman.