Honestly if even $1 of public money goes toward research, the work, data, journal, etc should all be public domain. End of story. That should be a basic requirement of taking public funds.
The current state of affair isn't a random thing. It's because the global policy of employment in public research and the definition of success is completely stupid and based on metrics (i don't care which metrics, the sole fact that we try to quantify everything just makes this kind of situations possible).
This is a major reason I am evaluating alternative career options.
The problem is in this case, researchers have to pay a further premium to journals (>£4,000 per paper). So this funnels further public funds to the journals
One thing that many scientists do is start businesses using their research, which serves as an incentive in the face of meager salaries. If not for the prospect of commercializing their work, many people might not even go into the field. In our capitalist system, this is unfortunately how things work.
So if you want to make scientific work all public domain, then as a society we need to make real investments into science to properly fund it. We also need to close the loop, such that large corporations who profit off this publicly funded work are forced to pay back into the system at a proportional rate. No more 0% corporate taxes, which cause money to pool at the top.
Having the articles freely available is good for encouraging discovery, communication and learning.
I don't see how that would significantly change the equation for protecting your business, as we assume the article was already available for 30 dollars.
If a 30 dollars fee is the only thing that stops someone from stealing your idea, it is either a bad idea, or your competitors don't realize it's a good one.