The market had already spoken by the time MS discontinued the project. Windows Phone reached a peak of about 3.5% of users and then started declining, quite rapidly.

Given that ~100% of money was going to the iOS and Android ecosystem, MS had no chance to retain even a few percent of the market: developers would not be interested in developing software for an obscure system that brings in no money, users would not be interested in a phone with little to no software.