It is bothersome to see behaviours that are irritating. These behaviours will not affect the world but it affects a certain individual. For example, a person who sneeze and use their hands to cover their mouth really irks me. It won't affect the world but it affects me. It's okay if they sneeze into their hands and wash it afterwards but usually they don't even care to wash it. We interact with people particularly by talking or using gestures. If individuals sneeze into their hands and someone ask for a handshake, it wouldn't be pleasing. It would be gross. The bacteria from the saliva that just got onto that persons hand would spread to other people who make contact with them.
Maybe a reason why people are engaged in this behaviour is because they think that to prevent their saliva from sprinkling is to cover their mouth with their hands. They are not aware that this behaviour is bothersome because if they are aware, they will use other ways to cover their mouth when they sneeze. There are other ways to cover your mouth like sneezing between your arms; arms will not be used to touch anything. Bacteria will not spread and others will not get sick. Another way is using tissue. Tissues can block saliva from getting onto people's hand.
I've been to many places where I've witnessed this behaviour a lot. I will share one experience of witnessing this. It was lunch time and my friends and I were in our school's open area. One of my friends was in that state of almost sneezing and I thought she will sneeze. I was right, she sneezed. She sneezed and used her hands to cover her mouth. I haven't addressed her or anyone else who does this behaviour because I don't have enough courage to do so. I feel that I don't have the right to correct it because it's their decision to do that.
It will be better if all of us will not use our hands to cover our mouth when we sneeze. It is gross and disgusting. It is not the proper hygiene and it is not healthy. We need to be clean, that way we can make ourselves presentable and ready every time someone ask to shake hands without any bacteria spreading away.