> Well, it's a $5 app on the App Store. ~$3.20 will go towards paying the indie dev, and most of the remaining ~$1.50 will go directly into Apple's coffers as a reward for doing such a good job locking down their operating system.

This is not a defense but merely a correction: The small developer program is 85%/15% rather than 70%/30% for anyone making less than $1 million per year.

The small developer program is opt-in, AFAIK the developer will be charged the full 30% by-default unless they explicitly apply.

You can rest assured that professional App Store developers have enrolled.