Just compare the essences for NIW and EB1, you will see why.
1) For NIW, you need to demonstrate the influence of your work on national interest and your peer's work.
2) For EB1, you need to demonstrate your national and international acclaim, that is, you are a nationally and internationaly recognized expert in your area, or your work has made a tremendous impact in your area nationally and internationally. Moreover, you also need to demonstrate the prospective benefits of your work to USA (The effect of your work on national interest will well fit for this purpose).
Nevertheless, your background should be strong enough for EB1; the format for EB1 petition letter is different from NIW's since their legal requirements are different.
Just for your reference!!!