I don't know about the personal feelings of those involved in making the anime. All I can comment on is what I see and what I see would draw me closer to believing that the anime mistreats Sanji than the opposite. But this whole situation is a catch 22, if you as a Sanji fan make a comment criticizing the anime than you're insecure/victim/cry baby and will be lumped in with the crazies who send death threats, if you don't voice an opinion then you still have to deal with the baseless slander that will migrate it's way to any discussion you'll have about Sanji which will ultimately force you to denounce the anime bringing you back to the first problem. The only way to win is to not play, leave Sanji to Oda and understand that you have the winning position when you post manga panels while they post anything but.
Now of course this saddens me because I look forward to seeing one of my favorite characters cool moments done justice and hell I don't mind the extra spices that Toei puts to make said moments even more epic but this isn't the case for Sanji at this point, in fact I dread to see how they will water down/misrepresent his good moments when they arrive. But any position I take at this point will only bring negativity towards me so all I can say is; It is what it is.