[josefx]

Sounds like a lazily written cli, typing help in bash gives usefull information and also refers to info. So you get an overview of the available commands and a description of the basics with minimal effort.

Meanwhile I can play hide and seek with the tools I need in Gimp for hours.

[ProxCoques]

Indeed. What if the cli had both natural language syntax, large alias/synonym matching, and command prediction (eg similar to Gmail's recent feature)? That might reduce the non-discoverability issue to about the same as most direct manipulation ui (where you have to look through menus for the "right" item to click on).

[cgio]

Mathematica has something akin to command prediction and it’s also a very nice way to learn the language.