These pedestrians are supposedly just hearing the echo of their own footsteps. There is nothing at the Betobeto-San spirit, this is nothing but paranoia. The Japanese have to stop the belief about this spirit since they are making it popular and this is what causes paranoia as someone walks, he/she will not be composed.
There is no scientific basis for believing that Betobeto-San, or any other kind of supernatural spirit, exists. There are likely psychological and cultural reasons which explain why pedestrians may believe they are hearing something they cannot see. Furthermore, the human sense of hearing is not as developed as that of certain other mammals: humans can be misled when trying to determine where certain sounds are coming from.
Throughout time, people have wanted to believe in spirits and ghosts. In reality, these things do not really exist. Even the Bible says that there is a great divide that separates living people from spirits. The only spirits that exist in the world come from God. People make things up, but it is only to comfort themselves rather than to actually respond to what they see and hear.
Many cultures believe in spirits and ghosts, and many people have seen or heard something, even when there was no possible way that something could have made the noise or been there. I believe that it is possible that there are spirts in the world and sometimes they do reveal themselves to us.