I'm not trying to pee all over IPFS. But it's also the case that it's easier to throw out mature, crufty old systems and start afresh. Every programmer knows this temptation.
We've had the web for twenty years now, and are just beginning to understand what it is and how it changes the world. If you're suggesting using IPFS (or any other system) as a way to expand and grow the web, I'm with you. But replacing the web means throwing out a lot of hard-won experience and intuition, in favor of a system that's bound to have its own issues down the line.