After Joe Biden, isn't the VP slot supposed to be open to whoever is willing to play the role of Court Fool, like Crazy Uncle Joe? Somebody who is put in the role solely to deflect criticism when the Boss needs him to do that? Somebody who guarantees the CIA won't assassinate the Prez, because then the Village Idiot who took over would be so much worse it would be too terrible to contemplate?
Kasich is not that guy. He may not be a very inspiring speaker, but he is a competent administrator. If he became VP and HAD to take over, he wouldn't be a disaster.
People in politics usually do not want their potential replacements to be people with a lot of political ambition, for obvious reasons.
Maybe since he quit the race, Kasich has had all his political ambition kicked out of him for good, and would pose no threat. I think he'd make a decent, respectable VP.
Kasich as VP would be a PURELY tactical decision to win Ohio in the General, and nothing more. I also think Kasich is a competent administrator and would be successful as a personable liaison for Trump. I would worry about his ‘left tendency’ influence upon Trump, however. If that didn’t happen I’d be more comfortable with Kasich as VP.