I have written a bit about this here, but the long and short of it is that the dogs provided a "safe" form of commercialization of heroic narratives in the USSR. In turn they help "humanize" space to the Soviet public, making it seem less the domain of robots and machines, and more a place where a bright Soviet future could be imagined. I am not sure exactly what other opinions you are asking about, but you might check out the post. There were also very interesting reactions to the Soviet space dogs in the West.