Was it really a lot of back and forth, though? In the beginning, they said not to wear masks so that they were available for health care workers. Then they recommended wearing masks in public because they are effective at reducing the spread of the virus and masks had become more readily available - especially as companies started producing reusable cloth masks. But even when they said not to go out and buy medical masks or N95 masks, it was still suggested to use some sort of homemade face covering. I remember going out to pick up dinner from local restaurants in April with a winter scarf wrapped around my face when they brought the food out to my car. It's not like they said "don't wear a mask" in March, then said "wear a mask" in April, then changed their minds again and said "no masks" in May, and then said "you really should wear a mask" in July. The recommendation changed from "don't buy masks" to "wear a mask" and hasn't changed since then.