The word "market" is just a convenient tag to refer to a collection of individuals like you and me looking to buy/sell goods and/or services, and deciding what's best for them given the choices available, their priorities, and the information they have.
Thus, when anyone refers to what "the market is willing to offer", they are referring to what the individuals like you and me who are shopping for a good/service are actually willing to pay in exchange for it.
Are you willing to pay a philosophy major a 70k/year salary for him to research a topic? No? Neither is anyone else. Thus, in short, the market for philosophy research is not willing to pay for that.