Lets say text based games had thier peak in the 80's, then belong there - and should be left there ...
I don't want to say you are wrong buuuuuuut.....
Text based games are some of the biggest money makers netting Fenexo 30k+ a month for stuff like Trials in Tainted Space, Corruption of Champions and Savin makes several grand on Corruption of Champions 2.
Lillith's Throne is making absolute bank.
Not to mention the masses of text based games that pop up monthly that seem to get players instantly.
So you are kinda wrong...
Edit- I say kinda wrong cos you aren't wrong completely, they are nowhere near as popular as they were back before my time.
They do have an audience though but so does everything if done right. Is all I was trying to say.