It's not just the one missile bay door.
It's one of many issues:
-Missile bay door
-Misproportioned fighter mode
-Tiny air intakes
-Legs stick out WAY too much in fighter mode
-Legs stick out WAY too much when linked to Tread
- Saggy inaccurate linked mode
- Tail fins don't tuck into forearms fully
.... and there are others I can't think of off the top of my head, all yours for the price of $200+.
If the thing only cost $100, we could say "Hey it only costs $100, so I can deal with all the inaccuracies and weird stuff."
But it doesn't. It costs $200+, which is a premium price for a toy with many questionable design issues.
Many of us want to like this toy, but for the price, we just can't. Personally, I could overlook the missile door and the fins not folding into the forearms if I knew that some of the issues were the fault of mistransformations. I hope I'm wrong and that the toy is much better than we're expecting. Unfortunately I don't think I'm wrong.