Why was Fitz a drunk in Olivia's alternate-reality day dream?

Fitz only became a drunk when he found out Olivia and Mellie betrayed him by fixing the election, and then his son was murdered.

Yet, Liv imagines him as a drunk in this past "What-If" episode, even though neither of the above things happened!!!

I am confused why the writers keep painting Fitz as pathetic, even in an alternate reality!

Why couldn't they just give the fans a happy ending? I mean, it was a fake episode anyway, right down to the Dream Wedding Scene.

Give us a strong and happy Fitz and Liv; a charismatic politician and a whip-smart fixer, with fulfilling careers... making babies and jam in a big old house. :)