I've never been much of a tools guy. I generally use what the default configuration is for whatever tool I use. It's just never been particularly important to me (and I don't feel like it's made even a small difference in my productivity as a programmer).
Projects like oh-my-zsh are nice because they provide a much richer default that lazy folks like me can use without ever having to know or care about how to actually configure a shell because the alternative is that I just won't do it. I'm not going to take the time to learn about the universe of configuration options. When I'm exposed to a feature it has to be really useful before I'm going to bother to learn about how to configure it. So plugins and the like are huge, they allow me to tailor my environment to the actual work I do with rich functionality that I otherwise wouldn't have.
So for me projects like this are awesome.