Malbim: This was to honor him more. Even though he was among the exiles, who were disgraced and lowly then, Daniel was in the first exile with Yechanyah. The Kasdim esteemed the first exiles, and belittled the latter. It says that Mordechai was "Im ha'Golah Asher Haglesah Im Yechanyah Melech Yehudah Asher Haglah Nebuchadnetzar." This was unlike Galus Tzidkiyah, which was via Nevuzaradan.