It's a fine question. I think the onus is on public regulatory bodies responsible for the standards; if they aren't able to pay for the work to be published as an open standard, it wasn't worth the cost.

Standards also benefit the industry as a whole, and it's generally in the interests of the companies involves to participate in the standardisation process anyway. Charging for the description of them is just a cherry on top (compared to e.g. licensing any relevant patents), I don't believe it's at all required to incentivize a standardization process.

(this is of course looking at interoperation standards - regulatory bodies are going to be more concerned with e.g. safety standards)