Indeed. When they say "it's fast", I don't read it simply as "the program is fast". They get their stuff done faster, and the program is simply a tool -- if further speed can be achieved with something else, so be it. It doesnt even need to be software.
However, I still think TUIs are in a better position due to lower development and maintainance costs. This can be achieved by GUI frameworks, for sure. But TUIs tend to be terser, and their natural limitations become an advantage when they make certain sorts of bullcrap (animations, for instance) undoable. I believe this contributes to long-term stability, as developers spend way less time dealing with useless requirements.
> the takeaway was that they really wanted the flow to be 100% keyboard-based
Good that you could draw such conclusion. I do think we should rely more on observation to find out what users need, as opposed to what they _say_ they need. I know this sounds condescending, but I dont mean that. I just believe thay it's hard for them to identify and verbalize some critical factors for their success and they need some mediation.
I also feel upset about the keyboard as a second-class citizen in modern systems. There's this UX design school of thought portraying users as creatures of extremely limited working memory, who can't even remember what they wanted when they clicked the option, and therefore need infantilized interfaces full of pictures and colorful buttons because they won't be able to memorize a handful of keyboard combinations