Michael wrote:

The national airspace system is full of those bugs.

The airspace classes are by no means an US national system.

This disconnect between authority and
responsibility in Class D is also a bug.

It's no bug at all. It allows a controller to basically say: "stay in
that region" or "fly that altitude band" or even more important "stay
away from that region", but I won't be able to provide separation.

If you're talking about bugs, then I'd say that the biggest bug is a
system which allows people to become pilots without knowing the basics
of airspace classification.

Stefan