Then why does John Boy say, "Is this it for us?", if this is only a temporary problem? Sure, they don't have enough money to make the repairs and continue to have parties in the immediate future and now they have to choose which one is the priority, but if they know that they'll still get funding after repairing the house with the money they have, why are they so despondent? Why are they acting like it's the end of the DIKs if it's only a temporary problem?
It would also completely undercut the point of the MC's speech if he was basically just saying, "let's support ourselves temporarily so we can fix the house and then go back to having Rusty's Dad pay for everything". The MC's speech was about him telling them that this is not the way things should be and that they should be supporting themselves through their own hard work themselves rather than have someone else support them.
This is meant to be a sea change moment for the DIKs, where they stop living the easy life and "getting everything for free" by working to pay their own way and to support each other and their frat. It would be absolutely meaningless if Rusty's Dad simply isn't paying for the repairs but will still pay for everything else. That's why Tommy storms out, because he doesn't want to do any work, he just wants it all handed to him but what he's become accustomed to has now changed for good and he won't accept it.
