In scripting languages, writing and sharing a new function isn't hard. And, if the language is open source, that encourages the rapid development of a community

In scripting languages, writing and sharing a new function isn't hard. And, if the language is open source, that encourages the rapid development of a community which implements useful and state-of-the-art tools. If every tool needs to be available through a GUI, then, as far as I can see, that GUI will either be a burden on creators or so generalized it's no better than tab completion.