"The market decides" is not relevant in this discussion. The decision to increase block sizes was not a market decision - it was renegade devs' decision. The same is happening here.

If you insist on framing it as a market decision, then the market has definitely chosen AGAINST arbitrary data (spam) on blockchains, since that was the selling point of all the various shitcoins - but they went to zero, and bitcoin went up. The market chose money being money, not spam.