There are no dumb questions.

What are the reasons that larger passenger planes don’t have whole plane parachutes?

There are no dumb questions. My little airplane dripping wet with people and bags weighed about 3,400 lbs. So less than a SUV. To develop a parachute that can handle that weight is practical. Now imagine how many tons a 777 must be, and you can imagine the size of the chute or the amount of chutes that you would need. It would be a huge penalty of weight and complexity. The theory on airliners is there are many, many more layers of redundancy that wouldn’t require this. There are multiple engines and systems that are backed up in different ways. On that little plane if you lose one engine, you are going down. There is no backup for that. So [a parachute system] is just not scalable. Nor is it viewed as necessary safety component for something as large as an airliner when you have so many other layers of safety.

So simplicity. And saving weight.