Looking for a command line utility or ruby gem that can convert a SVG file to a AI file. I've searched around quite a bit, and can't seem to find anything.
Does this not exists because AI is proprietary?
Two reasons AI is proprietary, and it reads SVG files. So there is no point in an SVG to AI converter unless you're using something other than Illustrator to read your AI files, which Adobe won't like. By loading and saving as native AI is effectively to tool you are looking for.