He still hated everything about him, he called him the scum of the universe etc. etc. Just because he spared his life doesn't mean he didn't hate him. Batman spares Jokers life everytime but he hates that man's essence, just like Goku hates everything about Frieza. If you don't see it you don't see it oh well, I thought it was pretty obvious though.
Ofc. Goku felt anger towards Freezer & hated him at some parts. But Gokus heart is pure. He ultimately didn't hate anyone. It was just for the Moment where he exploded. Just like Gohan against Cell. Gohan didn't want to fight & he didn't want to harm anyone but yeah you know well what happened.
What I'm trying to say is in the very end he didn't hate anyone because Goku is pure hearted. He hated them for the Moment when they did something bad to his Friends but in the end Goku isn't the kind who places a curse against someone. A Good exampe is Sasuke.
In the end Goku is always like .. oh that Freezer guy yeah he killed & slaughtered my friends but if he'd turn good hell I even would let him live on this planet. Just like he wished Kid Boo to come back as a good guy when he killed him. This is who Goku is, a kind hearted Man who at the every end didn't have any hate in him towards anyone. But I get what you mean with the hate towards him. King Piccolo is a good candidate here too.
