If there are all adults in the family and just one child, how can the interfernce by everyone in whatever child is doing can hamper child's overall development?

Having a lot of adults can have both pros and cons for the baby. I have seen this with my sister's 2 year old. On one hand, she learns so much from her grandparents in a fun way and also has a good time with her parents and uncle. This gives her the opportunity to talk to different people, get exposed to different modes of communication and handle different emotions — all while staying at home. On the other hand, at times she gets confused when 2-3 people are giving her instructions simultaneously. In her frustration to understand one of them well and follow their instructions, she refuses to do the task itself. Kids are smart though — she comes back to the task later and does it her own way. In a nutshell, more than hampering, I think it enhances the child's interpersonal skills at such an early age.