It's one of the biggest games they'll ever play in. Those guys play for a head coach who is always very animated on the sideline. They follow his lead.
Winning the game with Purdy in there for 4 quarters would have been no sweeter than winning it as they did. Their goal was to win the game and they were doing it.
Also, the Eagles saw what happens when Minshew took over after Hurts got hurt. It wasn't good. Saints and Cowboys looked very happy to win regardless of who the QB was and the win counted the same in the standings.