Text adventures as a category always struck me as kind of lonely. They often take place in environments where all the people have been removed, like miniature apocalypses.
It seems technically fairly obvious why this happens: other people are too hard to model. People have goals and expectations and so someone traipsing around trying random things is not generally acceptable, and creating characters that are disinterested in their environment is its own challenge. (Writing this I realize grumpy and stubborn characters are fairly common, maybe for these same reasons!)
In all these years of advancement in games the NPC still seems either lifeless or absent. I'm afraid I haven't actually played your games, so I don't know how you've tried to address it, but I'm sure you've thought about it. I'd be curious to hear any of those thoughts, but maybe specific questions:
1. Have you had any successes you could share in making a NPC seem "alive"?
2. Any ideas you were convinced were great but failed when implemented?
3. Do you think new technology can be applied to this? For instance it sounds like you are using more advanced NLP in Escape the Gloomer. (But understanding is only half, NPC motivation and goals seem equally hard.)
4. Does a strong NPC distract from the autonomy of the player? (Sometimes I wonder if people even want a strong NPC, or if players actually prefer NPCs to be background.)
5. And separately, have you tried AI Dungeon and if so what did you think?