The potential for government to slip into an oppressive role, as if into a comfortable pair of shoes, has always been there and now, we are starting to see how easily it can be justified. Every action like this, which may actually reflect good intentions, takes us down a path we should probably not be so quick to take (insert the "ism" of your choice here).
While it may have been possible, early on, to contain or exclude the virus, we are well beyond that now. If Utah, for instance, was totally virus-free, one could appreciate the attempt; futile though it might be. The thing is, Utah has not been virus free for a long time and as Rocky has pointed out, it would be impossible to keep it out with all of the traffic through the state.
Even locales which should, by rights, have been able to exclude the virus, have been unsuccessful in the attempt. Prince Edward Island, Canada's smallest province, should have had a real shot but were not able to do so.
Not usually an alarmist, I find it easy to believe this may be kind of a dry run or a probe just to see what the response might be. GD