At my old job non-technical people would navigate about as well as they would with a mouse and a graphical-based interface, because the graphical interface didn't provide any additional value. For those people it took the same time whether read instructions and press key or read instructions and click button. Trained people were definitely faster, and often the user would type ahead of the terminal (with no ill effects) because they were inputting data close to their speed of thought about the process [0].
The point is, for this situation a text-based terminal offered no downsides and many benefits compared to a graphical UI. I suspect the same is true for a lot of other business solutions.
I've heard it argued before that graphical systems are easier to use, but in my day-to-day experience in the trenches with others who actually used the systems this argument was simply not true. I've also seen it hinted that graphical systems seemed more modern, so they got less emotional disdain. That rings more true to me. And really if I were in charge of such things I would acknowledge emotional disdain - even misplaced - may well count for something in the overall business picture.
Also, and maybe most importantly, if the green screen needed a new feature or bugfix, there was one person at corporate that would do that. They had about a half dozen devs working on other things but she was the go-to for the green screen features. So I imagine it's harder to hire people for those sorts of systems nowadays. However it was also interesting for me to note that one person didn't seem stressed out or overly busy and the system never had a major crash or bugfix. So, tradeoffs.
[0] The terminal was actually hosted inside a wrapper app inside Windows 7. So I ended up using AutoHotKey to great effect to get even more efficiency gains.
* edit: added footnote explaining how AutoHotKey could be talked about in same breath as green-screen dumb terminals.
The point is, for this situation a text-based terminal offered no downsides and many benefits compared to a graphical UI. I suspect the same is true for a lot of other business solutions.
I've heard it argued before that graphical systems are easier to use, but in my day-to-day experience in the trenches with others who actually used the systems this argument was simply not true. I've also seen it hinted that graphical systems seemed more modern, so they got less emotional disdain. That rings more true to me. And really if I were in charge of such things I would acknowledge emotional disdain - even misplaced - may well count for something in the overall business picture.
Also, and maybe most importantly, if the green screen needed a new feature or bugfix, there was one person at corporate that would do that. They had about a half dozen devs working on other things but she was the go-to for the green screen features. So I imagine it's harder to hire people for those sorts of systems nowadays. However it was also interesting for me to note that one person didn't seem stressed out or overly busy and the system never had a major crash or bugfix. So, tradeoffs.
[0] The terminal was actually hosted inside a wrapper app inside Windows 7. So I ended up using AutoHotKey to great effect to get even more efficiency gains.
* edit: added footnote explaining how AutoHotKey could be talked about in same breath as green-screen dumb terminals.