When Bill Gates stated that US citizens brought back from China back in February were not quarantined is incorrect. The following article states that we did quarantine individuals upon their return to the states:
Texas Military Base 1 of 4 Approved to Quarantine Overseas Arrivals
Lackland Air Force Base in San Antonio could host up to 250 people until Feb. 29
Published February 1, 2020 โข Updated on February 1, 2020 at 10:48 pm
Again, President Trump did what he could and followed the counsel he was given by those who supposedly knew the potential harm if people returning were not quarantined.