Sometimes, when you are so deeply rooted within a world of your own, you begin to wonder how was it that you got this far? I have always dealt with hard decisions when writing a story because, in a way, I do not control the story... The characters do. What I write is strictly character-driven plots for the sole purpose of realism in the piece of writing.
I learned that because I plot out how the story ends up before actually writing the details of what and how things end up happening. Did I ever wish that I could change a decision for the betterment of my own satisfaction? Yes, did I ever do it? No.
I think it is very disrespectful when an author changes what he originally planned simply because they lacked the will to carry on with whatever they planned. Sure, you might have come to a new and better idea and justify it all you want, but the truth is, if it is something hard for you to write, imagine how the readers feel. Exactly, you want that.
I remember when I saw an interview of George R.R Martins where he spoke about how he wrote the Red Wedding. When it came down to it, he couldn't actually write it, but instead went ahead and wrote the aftermath of what happened, and then came back to it finally.