Why philosophy does not prove anything?

I won’t liken philosophers to a gang of blind wannabe zoologists trying to describe an elephant by touching her body from different positions. Philosophers develop and create new perspectives for old problems. As a by-product of their zeal they create many new problems. Nevertheless, each argument, by opening another peephole from a different direction contributes to enlarge our vision. Occasionally, one of those peepholes changes the whole picture.