Having skimmed the article, I cannot quite agree with you. I think the heart of the argumentation is right in front of your first quote where they write Withou

Having skimmed the article, I cannot quite agree with you. I think the heart of the argumentation is right in front of your first quote where they write Without a proprietary period, an astronomer with a brilliant insight might spend years developing it, months crafting a successful proposal to execute it, and precious hours of highly competitive JWST time to actually perform the observations—only to have someone else scoop up the data from a public archive and publish the result. This is a reasonable concern—such scooping has happened before. Without a proprietary period during which the astronomers who proposed given observations have exclusive access to the data, those researchers will have to work very quickly in order to avoid being scooped. The important thing to understand here is that an observing facility's data stream is not just a constant jumble of just anything they might have accidentally spotted in the sky; rather, you have to work hard up front to get a few minutes or hours worth of telescope time to look at a specific object with a particular instrumental setup. I think two assumptions are, then, reasonable: that all of the collected data should be made publicly available in their original and processed forms (because science and because of public funding), and that this should happen after the people whose research idea it was in the first place have been given a fair amount of time to work with the data.