I headcanon that his race is evolved for zero-g and low-g environments so floating is just...their first experience with the world around them. So at first it's an anchoring thing. Hang onto the adult so you don't float away. Then they experience gravity and falling for the first time and that naturally scares the Hell out of them.
...For the record I also maintain that Freeza's a closet sentai fanboy and the Ginyu are there because his dad basically bought him his favorite superhero team when he was a kid and they've been with him ever since.
and yeah one of the problems is that you either have those rare ones that put a lot of development into their characters and others who show up in your comments on a voice test just going RAAAAWR RIGHT ME.
It's like Yoda, except there's some of Yoda's family about but they seem hesitant to talk about details.and the ones that do aren't on DW