1. I think the fact that you have nothing of substance and have to read into the fact that after reading your comment explicitly mentioning tmux I repeated that illustrates the point is invalid.
2. but what's the value of a shibboleth if it's not reflected in capabilities??? Why would you care that a TUI app targets "tech user base" if you also know it will be less capable in your 'keyboard-centric' workflow due to platform limitations? And LCD for users just doesn't make sense, what user quality are you min-aggregating?
2. Again, it's not about the possible capabilities. Objectively, GUI programs contain a superset of possible TUI programs (since your GUI program could be a terminal emulator). It's about it being a shibboleth: I can be pretty confident that the TUI application will have a keyboard-based workflow, and I can be pretty confident that the TUI application will be targeting a technical user base, because those are the only people building and using TUI tools. The "lowest common denominator" in that sentence was referring to the users not the systems.