It's the only way it makes sense lol.
I don't mind though. Just like how it doesn't make sense for Gohan to train because he doesn't like it, it wouldn't make sense for Vegeta to stop because he genuinely loves fighting. The important thing is that it is now a much more friendly competition instead of the "I will legitimately turn evil if it gets you to fight me" stuff he did during his mid-life crisis in the Buu Arc.
Vegeta's grown up. I'm proud of the little guy.