How unrelated are they? Are they all made for different customers? Do they live in different directories? Are they all used for different projects? Are they all shared between different sets of people?

With git, the main thing to consider when creating a repository is "who is going to use it". Obviously, when for script x, you are collaborating with A, B, and C, and for script y, you are collaborating with D, and E, it makes more sense to have multiple repositories than if A, B, C, D, and E all work on x and y.

If it's just a bunch of scripts that live in your ~/bin, it doesn't make a whole lot of sense to have separate repositories for each. But I'd create different repositories for /opt/whatever/make-the-world and /usr/local/bin/silly.