What was the point of Elphaba's dad being at the send off at the train to Emerald City?

He didn't acknowledge her at all, if he just wanted to see Nessarose and put fear into her bf then why not choose a different day that isn't full of praise for the daughter he hates? Is he there supporting Elphaba, it seems like it's a big deal so it might be socially required, but then why don't we see him in the crowd as she gets on? It's just an odd moment for me.