Clearly what's happening here is that when Goku thinks of Bardock and Vegeta's father, he see's two proud Sayains, who faced the tyranny of Frieza head on and went down fighting.
When he thinks of Vegeta, he see's a Saiyan that that turned his back on the Saiyan legacy for the sake of self preservation (hence why he is further away from Bardock and King Vegeta).
As to why he is naked with his cheeks exposed to the symbolic threat of Frieza..... I don't think I need to explain that. All I'm gonna say is that Frieza was his boss....
Stan for a so-called "Prince" that was submissive to a space tranny brehs
Edit: And I don't stan Goku. Yamcha the realest member of Earth's special forces