Why "Joe/Love aren't real so its okay to romanticize them!" doesn't work
As the old saying goes - "art reflects life". Yes, the specific characters of "Joe" and "Love" are fictional, but they are based on real life people/behaviour.
Joe violates women to feel a sense of power over them. This is literally how predators and rapists operate. He also gets violent with women for showing autonomy (e.g. kidnapping and trying to kill Candace for dumping him, same with Marianne, strangling Beck for standing up to him etc). This stuff happens. It is not romantic or cool or badass or hot or whatever Joe fangirls like to call it.
Love breaks people in order to make them depend on her. Like Forty, making him think he's a terrible murderer. This "break them to save them" beahviour happens in real life. And she shows the same entitlement like violent energy Joe shows to his love interests to James when she murders him for wanting a divorce. It's just a gender bent version of what he does. Not to mention she is a huge internalized misogynist and victim blamer "Guinevere Beck was unspecial and mediocre, she didn't deserve you (you = the man who strangled her to death)".
Also a statement that will hypocritically annoy these same people who make this case for Joe/Love:
Beck is a queen for cheating on Joe. And lying to him about it.
I mean... It's fictional? So why are you so upset about it? #GirlBoss #ISupportWomen'sWrongs