It's not the fact you have them, nor the fact that you think you are special.
By saying things like 'be proud of your battle scars' it makes those of us without stretchmarks fell like less of a parent/ made less effort when we had a child. What can we say? Hmmm.
It annoys me too no end. I wish I had earned tiger stripes, but I didn't, but I still gave birth, so why am I not worthy when a stretchmarked mother is?