That's just the point. A diving certification isn't a license. It's more of a certificate of training. If some one with a boat or an air compressor requires such a certificate before they will deal with you that's their business but in most places there are no laws restricting diving. You don't need a license to dive. You don't need any one's permission. You can walk up to a lake river or ocean, gear up and jump right in.
True we have to renew drivers licenses but all I ever have to do is pay money. They don't test my driving ability.
If we were to be somehow forced to renew certifications (that'll be the day!), what agency would I have to renew with...IANTD, TDI, PADI, NACD? What kind of refresher would I have to take...OW, AOW, rescue, full face mask, dry suit, night, wreck, ice, nitrox, nitrox, trimix? What? Or maybe I'd just have to demonstrate that I can kneel on the bottom correctly?
Maybe all? Maybe I'd have to be doing refreshers every week just to get one of each in every couple of years.
You folks buy cards that need to be baught over and over if you like...me? I'll just dive when I want.
I'll never get over people. When we talk about the poor quality of training and how it can be improved they argue in favor of leaving it the way it is but then they propose manditory refreshers and ongoing payoffs to the agencies that failed to teach them correctly in the first place.