As a tech guy who went to a game programming school, my personal theory about why technical people get hung up on engine development (the old "I'm making my own game and have spent the last year writing my own engine") is quite simple - it's just an easier problem space.
Writing an engine has a defined, knowable set of steps that you can answer with if asked "What do I need to do to write a game engine?".
On the other hand, how do you answer the question "How do I make a good game?".
So people get stuck writing engines because it's interesting and because they can feel like they're making progress on something.
As a tech guy who went to a game programming school, my personal theory about why technical people get hung up on engine development (the old "I'm making my own game and have spent the last year writing my own engine") is quite simple - it's just an easier problem space.
Writing an engine has a defined, knowable set of steps that you can answer with if asked "What do I need to do to write a game engine?".
On the other hand, how do you answer the question "How do I make a good game?".
So people get stuck writing engines because it's interesting and because they can feel like they're making progress on something.