I imagine some folks were hoping for a romantic ending, and found this disappointing. I thought it was refreshingly real -- the main character is competent and has a full life, she is not a "flawed beauty" as most rom-com leads are. The romantic interest (spoiler) isn't going to win despite his enormous failings. Thank goodness for that.
My only beef is the body image stuff - fatphobia isn't a good look. Some might say turnabout is fair play, men say this stuff about women all the time, but really, it wasn't necessary.