And generally I feel it's a valid argument, but it exposes two root problems:
1) Scale: There is a clear difference between a single person photographing license plates in a parking lot, or even a single person following one car, compared to an enterprise industrializing that tracking process through wholesale procuring of security camera footage or similar.
2) Linkage: Even if your license plate can be tracked, why should it be linked to your identity? The answer is that it really shouldn't. Of course you can register your vehicle to an LLC, but even if you don't do that, you shouldn't expect anyone on the road to map your license plate to your address. But again we return to the problem of scale, because ultimately someone could see your car in your driveway, then see it on the road, and therefore know your starting location and current location.
The first problem of scale, while clearly exposing an obvious difference, doesn't seem easily resolvable to me, because at what point is a process "industrialized?" How do you legislate against this without imposing on constitutionally protected activity, or at least basic pseudo-freedoms like freedom of commerce? And how do you avoid regulatory capture granting carve outs to a few anointed large corporations to continue the practice, especially if they're the same corporations that "contract" with the government? [One side-problem/solution here is the lack of transparency of, or restrictions on, government purchasing "public" data.]
The second problem of linkage, seems more easily addressable (no pun intended). States should put more protections on license plate databases, and make it easier for people to register their vehicle through a proxy, even without needing to create an LLC. But you still have the problem of "manual" linkage using photos of driveways.
But the larger, perhaps root issue, is that modern technology is exposing a middle ground between "private" and "public" (meta)data - we see this with enterprise-scale tracking of public information, and also with "personal data" shared with limited audiences on social media sites, where it's obviously not private because you intend to share it with people, but you also don't intend to share it with everyone.