Would you edit a painter?

I'm kinda having mixed emotions about editing. I certainly understand the need for editing in regards to spelling, grammer, punctuation, etc. but I am having a difficult time at the thought of someone telling me what to take out of the story and what to add. When Piccaso, Chegall, Cezanne and even Peter Max were starting out I'm sure they were told what should and shouldn't be done but weren't they all great at their art when they were finally free to truly express themselves?
Story editing really is just trying to please the editor, not the author, not the characters or the audience. One of my favorite stories about that was from one of my favorite authors, Dan Simmons, who said the editor at the publisher for his book "Carrion Comfort" told him to "keep the title, rewrite the book"! What?! How dare you tell an artist to keep the canvas and repaint the picture!
I say all this because I had my first experience (another first!) with a friend who offered to edit my book for free instead of paying the publisher for the service since I am self-publishing. She enjoyed the first chapter but the second one had so many marks on it I really wasn't sure what I was supposed to do with that. I made obvious grammer or structure corrections but kept the story as is because that is the story. I cannot have the rest of the story without background. I thanked her and decided to revise the book and send it for publishing, paying for the editing process. I know she was just trying to help and she is an English teacher so I was hopeful but all I really wanted was grammer and punctuation correction, not for someone to tell me I am writing the story wrong.

I don't know if I can have the freedom to express myself in my writing and have an editor. Need to do alot of praying about this one.

(sigh)