I don't know. It doesn't make any sense that someone would be against a UI for something. It is just mostly a bunch of volunteers working on their own projects. I could see a volunteer saying something like "nah, I'm OK with it the way it is" because they are working on something for free, usually for themselves and sharing it for others to use and/or contribute to.

It seems odd that you'd complaining to some project maintainers and calling them elitists for not working on your suggestion and even odder still because I'd imagine many would be thrilled for someone to contribute to building a UI, even if it's just mock-ups. Unless you're talking about some random people in the Linux community but I don't really see any point in doing that since they probably have nothing to do with whatever projects you're talking about.

What would adding a GUI to a command line app even change about it as far as the command line? It isn't as if you either get one or the other; you can have both. It just doesn't make sense.