I know that WiS has said in the past that they have intellectual property concerns about giving away that much data in such an easy manner. In other words, a lot of the value of the game is all the ratings, and if you could dump out the universe of ratings for the world, it would go a long way to reverse enginerring the engine
It isn't my place to comment on how likely that is or not, but it is a legit business reason for not providing something that clearly would be both easy to implement and a valuable tool for onwers