The issue is less whether it's going to be a dud, and more whether it's going to be absolute carnage, as wide boulevards narrow to little cobbled streets and every sprint team, GC team and classics rider wants to be at the front. There's a real risk of losing a jersey wearer or podium placed rider on the final stage, which I'm sure some will find entertaining.
Personally, I think the sprinters who've dragged their heavy arses over the mountains deserve to keep their "sprinters world champs" and the early stage drinks and photos serve as the Tour's closing ceremony. The peloton has fought for three weeks to get here and to determine the yellow jersey, it's fine they take a moment to reflect and pose for the cameras. It's fun to see the Danes (or Belgians, or Brits) gather across teams for a photo. And yes, it's still a proper stage - as much as any other non-GC stage - competition-wise it's no different to 230km into a boulevard sprint in Bordeaux with three riders (one from Cofidis) in the break.