Jones is 22 with a child, if the NFL gets in his ear telling him he can make a team, you go get all the money you can while you can. As for Braxton, I noticed during the game that Barrett was on the headset and jersey right behind Jones all night long, Braxton was in street clothes, standing by himself not really engaged in the game or with the team. Came off as a very "me first" type of thing to do, maybe reading too much into it, but my friends who were over noticed it as well.
Edit, there is even a thread about it on 11warriors, apparently a lot of people noticed it
http://www.elevenwarriors.com/forum/ohio-state-football/2015/01/47502/braxton-miller-on-the-sideline