In theory GUI is a superset of TUI, there's nothing inherently bad or unproductive about GUI. You can argue in practice there exist a lot of unproductive GUI that's worse than a TUI client, but I think it's the problem of the designer, not the tool.
Also there are some areas that's universally acknowledged to be better suited for GUI, anything that requires visualization like video editing, image editing, 3d modeling, etc. Maybe someone can go full ffmpeg to edit a feature length film, but that'll take some effort.
Only if the TUI is non-scriptable. That's the big bait-and-switch possible here: Is it a TUI in that the menu system is made out of text, or is it a TUI in that it's a command line with a scripting language and the ability to create new commands out of composable pieces? Just saying "Textual User Interface" doesn't disambiguate the two.
How com GUI isn't scriptable? Most GUI is made from scripts. Or do you mean the ability for end user to extend the software with a software-provided scripting system. In that case that's not related to GUI and TUI, all application no matter GUI or TUI can be extended by scripts if the software author wants to support that.
Also there are some areas that's universally acknowledged to be better suited for GUI, anything that requires visualization like video editing, image editing, 3d modeling, etc. Maybe someone can go full ffmpeg to edit a feature length film, but that'll take some effort.