My computer is not neutral. It is mine. You're free to relay what you like.

The idea that Bitcoin should somehow be neutral in all ways is an odd one. Bitcoin is money -- something that by its nature is designed to keep score. To let us see the winners and the losers.

That it is even possible to upload jpeg's to the blockchain is simply a failure for developers to solve a technical problem: how to prevent it without impeding the ability to manage the monetary use of the network.

As such, we can't (yet) stop the spam from getting through. But nothing says any of us needs to take part in actively assisting it in doing so.