well, i am from kbin and the people i have migrated are also on kbin, there has never been any confusion, it's made migration really easy. i have been told lemmy has intimidated and put off migrants by those migrants themselves. i think initially people should start on kbin, they will grow a natural understanding about federation and the fediverse, and from there they can choose if lemmy or others suits them more as a platform.
If i had to guess, one single platform is something people new to federation can easily understand. What happens behind the scenes is nothing the average user needs to know or should even notice. Time will change that understanding, this is just the beginning and there should not be a rush because that will scare people away.