While the IPFS whitepaper and spec does utilize a lot of modern technology terms, it does not mean they were assembled without serious consideration and purpose. What gives you that impression?
All of those pieces have important properties which create the essence of what IPFS is. When you say Blockchain, Git, BitTorrent, I hear: Directed acyclic graphs (like git) with hashed hierarchical checkpoints (like a blockchain or merkle trees) distributed peer to peer (like bit torrent). This is literally what IPFS is, and using those terms is one way to describe it.