What you are saying has merit but is missing quite a bit of detail. The one that they didn't shoot down (until it crossed the entirety of the United States) was huge and loaded with technology capable of spying on the US. These ones they did shoot down were likely hobby balloons.

So they did nothing while we were spied on; queue public outcry.

Then they wasted a lot of money and effort to blow up something to try to distract us from their inaction the first time around; queue public outcry.

The details matter.