You are calculating 150,000 dead Americans assuming we lock down society and the economy, as Italy has (belatedly) done. But it would presumably be much more than that if we decided the economy is more important than Grandma. Also I fear that your projection of 30,000 fatalities in Italy will be on the low side, they have already surpassed 8,000 and have been averaging about 700 per day for the last few days. At that rate they will have surpassed 30,000 in about a month. This article has a sobering graph of how the number of cases is the US is accelerating faster than in Italy: https://www.vox.com/future-perfect/2020/3/20/21179040/coronavirus-us-italy-not-overreacting
Nobody is saying the economy is more important than Grandma. Selectively opening parts of the country to certain people is not telling Grandma to drop dead