You can make oblivious storage (and even ORAM) on top of IPFS, without too much work actually. A critical point here is that making something oblivious by default is a nonstarter for 99% of users on the internet, because major consumer and corporate applications would never use something that (a) adds that much latency to requests, or (b) may have pushed "bad bits" to their computers. This is a design constraint BECAUSE of adoption.

The point is to establish IPFS as a base layer, and build the oblivious storage platform on top.