The FTC's job is to protect Americans from businesses that cheat. This is them, doing their job. If the Supreme Court strikes this down, it further delegitimizes the court, and spells out exactly who the GOP works for.
This is part of the long history of antitrust and labor. From its earliest days, antitrust law was "aimed at dollars, not men" - in other words, antitrust law was always designed to smash corporate power in order to protect workers.