I mean, technically the distinction between a file and data (and anything digital really) is rather arbitrary ¯\_(ツ)_/¯
Agreed! 
However I was mainly responding to OP who said: "My idea is nothing but to come up with a standard for storing files on the blockchain, so Alice can put a file on the blockchain with a certain filename, can give that filename to Bob and Bob can read the file without too much pain." and then saying: "See, even Microsoft does this now". In that context: storing a small amount of data using the standard OP_RETURN is not the same as Microsoft now storing files.