Another reason is that playing DraftKings or FanDuel does actually make watching football more interesting- you care about games you otherwise wouldn't care about. Many people will happily continue to lose $10/week for the benefit of enjoying watching the NFL more.
Online poker isn't as fun when you're consistently losing money- there's no "outside" benefit.
Online poker isn't as fun when you're consistently losing money- there's no "outside" benefit.