Jon is responsible for formation of United Planets. I think Bendis was thinking that in this way its more logical to see Jon leave for the future. It makes sense in terms of the beats of the story. But how could Bendis be so unaware about LoSH and Superman?
Just take out the last couple of panels it could have been wonderful. Let Jon decide for himself that he shall go. A good character is one who takes the initiative. Take steps into the unknown for an idea whose time has come. Let him come up with the idea of United Planets. He did that a few panels ago. That isn't an issue. Its the line by the LoSH which ruined everything.
If Jon volunteered on his own it would be different. Superman would have opposed Jon's going. But Jon would stand firm. He is a (young)man out of time, in his own time. He is the one best fit for it. It would be the first time when Jon really opposed his father for something bigger then everyone involved. The way its written it looks like Jon has little agency of his own.
I am dissapointed. Superman did not make the United Planets. Sigh.