I guess Shapiro being a jew was too damaging to the pro-Hamas/Iran wing of the party.
It's no surprise that's your guess.
To the conservative, it's never anything to do with what's good, or qualifying, it's always everything to do with what's bad. As always, with a normal tinge of bigotry.
For example, it's not about Walz's strength or credibility that earned him Democrat nomination for VP, it's because Shapiro is a Jew. And the Dem nomination for POTUS, a sitting VP, former Senator and state AG is a DEI candidate.
Which, in part, explains why the GOP has lost every election since they crowned Trump.
Which of the people involved were previously identified as 'the best' that could be hired?
There were good people on both sides.