In the mountain terrain I hunt and the amount of hiking I do with a rifle it is important to me that I have a clean clear scope to look through at a moments notice. Without covers, its inevitable that I will get leaves, pine needles, dust, dirt, etc., on my scope lenses.
I also have scope covers on my tactical rifles. My preference is to protect my investment with a set of scope covers then chance damage to expensive optics in a hunting or tactical situation.