For those that like to write letters, it is important to have the greatest possible area to write and that any designs on the paper itself do not overpower the writing itself. That is, while it can be fine to some gorgeous artwork on the page, it needs to be secondary to the writing itself. Minimalist stationery embraces this concept beautifully, creating an ideal surface for the person to create their story and for the recipient to read it.
The stationery is still attractive, just that it tends to the pastel and simple, sometimes even to the point that it omits the address and other identifying characteristics normally associated with stationery. This gives it a simple elegance, making it ideal for someone who is more interested in making a point than in making it hard for that point to be seen in the clutter.