Designing for the whims of “the market” is like living your life according to the dictates of free advice.
Take for instance crowd sourcing, and other forms of "big-data" driven decision making processes. Consider the problems: confirmation bias, mob rule, domination of our darker, baser nature over our higher order thinking and moral core on average.
Consider using social media, internet forums etc... to train AI chat bots or social media bots, and how those primitive AI's express themselves.
Consider a ship at sea as a metaphor. In this metaphor navigation of the ship is the design process. The currents of the sea and the wind and the storms that toss them are the whims of "the market" in this analogy. And thus designing according to the whims of the market is to remove the rudder from the ship, and to throw out all rational methods of navigation.
Consider art made to appeal to the masses based on the buying habits of people the artist (or design team) has never met versus art made from visceral self-expression and the solidity of self-knowledge derived from life experience. Alternatively weigh trying to appeal to everyone versus a specific community of shared interest.
These are just some thoughts I have yet to coalesce into a coherent essay on this subject. I may never do so, and so here they are thrown out there before they are buried by other more pressing thoughts and forgotten.