Honestly the fault mostly falls on Oda....
Like let's be honest... I am a man who does not hit women, in my life, it's natural to get angry at a woman or get provoked by a woman, that's life, it happens, and maybe I might face a woman who just pushes you to get angry and ht back, BUT to avoid such thing, to avoid hitting a woman, I just get out of that place, and avoid to be in same space.... It's something normal people can avoid to resort to violence...
The problem here is that Sanji does not hit women, BUT Oda arc after arc, he continues to just plot Sanji in that situation....and not only that, but somehow, Sanji forgot that he has a tool like RS that can make him invisible to run away from that floor and escape, SOMEHOW... Oda just forces Sanji to be in that situation....
Sanji would not get the same backlash or hate if Oda ONLY did this one time in the story, and we just got to know who he is, and for the other arcs, he made Sanji away from women opponents.... but the problem is that Oda is on continuous repeat for the SAME PLOT, over and over again to a point people started to hate him for it...
So for me, I do not hate Sanji's actions, I rather just hate Oda's script of STILL putting Sanji in same plot over and over when we know the outcome, which actually does not correlate to reality because in life, we don't fall in same trap over and over again, if I do not hit a woman and had a bad day with one, I do not face the SAME SHIT over and over again in other days and other years.... unless you are married to that person, but you can easily divorce if she is violent... it's all on Oda for me