Not to forget about the snake, which revealed the death threat was a lie. God had no control over the snake. Design flaw? Beyond his powers? A part of the character test (but God punished the snake as well, so that's another vote against that theory)?
The snake was looking forward to see Adam and Eve get in trouble. Not exactly a character trait you'd want to write home about.
It's basically a metaphor for regimes trying to keep you illiterate, and considering you a threat once you become educated, draw your own conclusions, and make up your own opinion.
Regimes never ask why you did something. All they care is that you did it and that you get accordingly punished for your disobedience. You're making it too simple.
But there is also another metaphor that comes to my mind: You don't bite the hand that feeds you.
Bob