Here's my (incomplete sample)

- difficult to find luggage carts,
- luggage carts not allowed in elevators,
- not enough mechanical stairs, especially when you try to move between subsections of T1,
- filthy eating areas,
- not enough space between check-in counters and doors,
- not enough immigration officers,
- immigration officers with serious attitude problems,
- RER staff with attitude problems
- poorly trained RER staff
- confusing, misleading and/or incorrect signs
- not enough space in baggage claim area
- must deplane to unsecured area and thus go through security again when connecting
- impossible to communicate between the satellites in T2 without leaving secure area
- RJ parking area extremely far from terminals...
- not enough seats near gates
- two flights departing at same time from adjacent gates with same trunk

The list goes on. Do you need more?

As for the "avoid airport lists", interesting to read that this article actually gives CLT as one of the best...