Why did she cast the most French actor possible with the most French accent to (spoilers)

be the old, ugly, fat and dour German professor from the novel? And have him brooding over her and following her around like a lovesick teen?

I guess Greta agreed that Friedrich Bhaer and his "romance" and marriage with Jo the most forced and absurd plot in the book. But if Laurie isn't right for her, how is this older and uglier version of him following her around and lapping up after her going to be any better?