Dark sky is not a public good, it's a for-profit business that puts a shiny interface on the same information available to everyone. It also added user reporting and analytics, so added material value. The app cost money. Why don't you lobby your congressman to have NOAA develop a better app instead? You can't make a privately-developed program a "public good"; citizens can't just "demand" that dark sky remains independent and expands because they didn't pay for it. Either lobby the government for a better app, wait for the private sector to develop a better app, or lobby the government to attach a license to the data prohibiting commercial use (though this would kill the other apps, too).
You might re-read my comment. Nowhere do I say Dark Sky is a public good. I do lobby my congressperson for NOAA to have more open data practices and better funding for app development. Citizens can demand products from government be at parity or better than private corporation products, and government has the funding to do it. So why not do it?
I'll note that you edited your comment after I posted my reply, and are now making it sound like you didn't. It originally included something to the effect of, "This shouldn't be allowed to happen."
I made no such edit, and at no time made such a statement. I take no issue with Dark Sky being acquired (EDIT:) and my comment is only to vocally advocate for government-run services that cannot be acquired (to provide continuity of quality service and delivery of data products to citizens and the systems and apps they use to consume said services and data products).