The problem is that work on standards costs a lot of money. Somehow we need to pay for that. The solution could be the state.
Standard is created by volunteers typically sponsored by their employer to go to standards meetings, who also pay (depending on national body) for being members.
The standard organization itself has and needs some infrastructure to exist, and that has to be paid for.
While the folks getting together creating the standards are (often) sponsored by their employer, the employer thinks this is a net benefit because they get a say in setting it, after which they can turn around and sell more product(s) based on the standard.
The standards organization themselves do not have such an option, but they still have bills to pay.
Adobe has an interest for more and more people to use PDFs because more people will then buy their products.. if they're afraid of the costs, don't publish the standard and risk people switching to other stanards.