Certification cards are like "credit cards". They are easier then heck to get. You can go beyond your limit and no one is going to say anything most of the time. If you do get in way over your head, more than just you usually suffers.
No offense, but when referring to cave certs, you're dead wrong. I have to repeat my intro to cave class next month mainly for missing 2 hand/light signals. We had 3 people in our class, 2 of us have to retake it and work on some things in 2 weeks, and the one who passed was taking it for the 2nd time.
Instructors don't take lightly to sending students off in caves who aren't prepared. Not only do they lose a student, they lose a friend, as does everyone who that student then goes off and starts diving with. Anyone who takes a cave class must be prepared to repeat it, there's simply no way around that, every instructor makes that very clear. You're being watched by at least 1-2 divers at all times, some instructors bring former full cave students in as well so that 1 person is watching you at all times. ANYTHING you do that's different from what you usually do is going to get questioned.
Instructors who certify poorly skilled divers get talked about, and the word spreads quickly through the community. One student can really hurt your reputation. Trust me, they think about all of these things. Stop by a dive shop near cave country one day, you'll quickly notice how many people seem to know each other on a first name basis, there aren't many secrets.
I do agree that AOW cards don't mean jack squat, but tech cards do. I know where you're coming from, my nitrox class had someone in it who couldn't even read dive tables, so she was told to go buy a computer and passed on that agreement. My written test for intro to cave had questions about omitted deco, repetitive dive tables, and staged decompression, all were to be done with no help. You're not even allowed to deco for intro to cave, these questions were just there "just in case" it's hit on accident. There's a HUGE difference. One or two bad cave instructors are out there, I'm sure, but let's not generalize the industry on what the minority do.
I know of at least one cave instructor (GDI) who posts on here. Hopefully he'll chime in.
To the OP-
One thing I forgot to mention that could be what you're seeing, is cave/cavern divers who are just screwing around in open water when they dive with you. I know for a fact that I'll do back flips and various other things that cause me to go vertical in the water instead of the horizontal trim I've been taught in cavern/intro, heck sometimes we even take one of those underwater football things with us and play catch lol... I don't lug heavy steel tanks around if I'm diving with someone wearing an AL80, I'll wear an AL80. Sometimes (this weekend) I'll wear a jacket BC, with full rec gear, just because my regs are already mounted on my doubles, and I'm too lazy to swap them over.
Also, places like Ginnie springs, FL state parks, etc all require to see your cert cards before diving. Since you almost always check in with a buddy, that solves that issue.