It's true only for the very basics. Applications adopting vim shortcuts, or using readline, take on the most rudimentary navigation shortcuts. But that's not what I meant about weird shortcuts doing text magic.
Consider e.g. e-mail in Emacs[0] as on this screenshot: [1]. Both the list and the message you see on this screenshot are read-only UI, like in any terminal-oriented app. Except that I can navigate through and manipulate them with all my usual Emacs shortcuts, including:
- using incremental search to find a message of interest
- doing regular Emacs region selection over multiple messages, to apply the same action to many of them
- semantic expansion of selection
- using selection to spawn multiple cursors at appropriate places, and then apply the same actions under each cursor
- using M-x occur to do a "grep" on contents
- using regexp highlighting to highlight lines or words matching regexp
- using narrowing and widening to display only a subsection of the e-mail list
... and many more, and all those examples didn't even touch e-mail-mode-specific things! That's just text-editing shortcuts over text UI! Those are all the things you'll have in your muscle memory as a proficient Emacs user, and you can use them everywhere - be it IRC, terminal, a REPL, list of e-mails, etc.
In this way, "Emacs OS" UX is superior to my "host" OS UX (be it Windows or Linux), because I can perform all those actions in an unified way, without breaking my flow - and I have access to very advanced/complex actions (plus the ability to write my own, or download them from the Internet).
Oh, and even if read-only, the UI is still text, so I can just mark it all, copy over to another buffer, and process it as if I was working with a plaintext file. No need for scrapping anything.
EDIT: changed "expansion" to "widening" in the point about narrowing.
--
[0] - which I just managed to get working, thanks to friendly HNers that responded to me here: https://news.ycombinator.com/item?id=14569833.
[1] - http://i.imgur.com/JpnxZSl.png