CDC and other major institutions are looking out for the many not any one individual. They don't want there to be crazy private demand for masks competing with health care professionals.
https://www.imperial.ac.uk/news/196234/covid19-imperial-rese...
Shows that the pandemic and associated social distancing measures may need to go on for months. How does the CDC switch messaging from saying that masks are useless to "well you should wear one now since you're going out..."