It's all down to each person's use case. I personally would welcome an improved camera on the iPad Pro as I do with the other iPads. I use the iPad a lot in the house and if the kids do something entertaining then I will snap it with the iPad. An improved camera would be welcome for this alone. Same applies to the Facetime camera on the front as an improvement there would be welcome. I also use my iPad to snap pics of items I'm selling on eBay or Gumtree so I can do the selling from a single device. Again, an improved camera means better quality images for the buyer to view.
Holding an iPad up in public may not be the best scenario for photography but there are plenty of scenarios where a good iPad camera does make a lot of sense.