It won't let me quote the comment above,
However, having watched enough of these dramas and read enough of these Mangas, I can say she never dreamed of being a teacher, she literally made that up in the spot. You can see her panic about not having a dream even before Zuo An says he's going to America. Also, every time it's brought up afterward she looks like she wants to say that isn't actually her dream, but can't because it made her dad happy. If anything I would think her original dream would have been to stay in boxing, but she wasn't given that chance.
But I will agree with the title the ending of this drama was a disappointment, but with this genre being so played out recently they needed to think of some kind of new ending. But that kind of ending isn't why I watch these types of shows. Also would have loved it to completely break and have Xiao Man end up with Shen.
As for the PYHOMS comparison, they are only comparable in the fact they are both fluff and cover college. Their base genre is completely different.