I think you are letting your narrative get in the way of reality. Since the end of the 2012 season, the White Sox have only twice traded prospects for MLB pieces: this Frazier deal, and the Samardzija trade last winter. That one last winter turned out poorly, obviously, but Semien and Phegley don't really represent "core" players, and many observers don't think they are giving up any such players in the Frazier deal either (many have Montas pegged for the bullpen eventually). They've actually traded MLB players themselves far more often, most notably Peavy and Hector Santiago, but also lesser deals selling Rios, Reed, etc. Additionally, they haven't forfeited any first-round picks for their various free agent signings (even their 2016 pick is still protected, if they want to sign someone yet this winter), and they actually netted their own compensation pick for Samardzija next year. You can go back even further too and you won't find much actual evidence to support your claims. Aside from Eduardo Escobar in July 2012, I think you have to go back to 2008 and Gio Gonzalez to find a prospect they traded that became a "core player" (and even then, they actually acquired Gonzalez a year earlier for selling Freddy Garcia). They are obviously not perfect, but no, they haven't been selling the farm.