Yes and no, or "yes, to some extent".
Cases when I do agree with that statement:
- Radical change to the post, e.g. changing the whole idea behind it.
- Minor and unimportant syntax changes, e.g. changing "color" to "colour".
- Trying to improve with own ideas of the editor, with which OP disagree. Kind of like #1 above.
In such cases, I believe OP has the right to edit, and I'll support it.
Cases when I disagree with the statement:
- Editor removes "thanks", "hi", etc.
- Editor improves formatting in the post.
- Editor retagging properly.
In all above cases, and more (any truly valid edit), I would fight the OP for the sake of keeping the place clean and organized. Did it more than once, will do it again.