The viral transmission rates are far too high to use community spread protocols and contact tracking and isolation do much good to check or even slow rate of spread. The system would just be overwhelmed .
We are really only 5-6 weeks into this thing and you simply cannot turn things around much faster. Original tests gave > 50% false negatives. This bug is sneaky and harder to identify - same things that make this virus hard for immune system to detect make it difficult for reliable test.
Reality is aggressive social distance is only solution at this point. All testing would have done is confirm that fact. In fact, if we did have tests, natural response would be to wait until results came in - that indecisive waiting period could have proven highly damaging if things things are going badly in a big way
Personal opinion based trends is that we caught it early here and have a good shot at moderating spread to minimize ultimate damage
Tests will be very useful tools going forward but no way we could have developed and deployed enough reliable test kits to make a difference in 4-5 weeks
We pretty much could glean those insights from the Korean testing. If anything I would have taken the approach of pouring resources into Korean knowing they would be the center point for testing to gain insight. Why reinvent the wheel?