There is a 'false sense of security' argument against masks but it gets mixed up with all the humbug reasons not to support mask wearing in this country. So I will keep an open mind about how masks and the attitudes around them may evolve.
They don't help. This virus doesn't just enter through the nose and mouth and the masks most people are wearing are not going to block the virus anyway. A lot of people don't know how to put them on properly, hence the WHO advice. As you say they give people a false sense of security and even putting the mask on involves more touching of your face.