Have to address this. Yes, Garvin was a poor choice and that is exactly why he only had a short reign - fans didn't accept him as good enough and for good reason, he'd never held a position higher than midcard in his career (and he was 42 at that stage).
Sting was a completely different kettle of fish - the NWA preferred heel champions like Race and Flair for a very simple reason: the territories. Thus, the heel World Champion would role into an area and take on the hometown hero in a series and then move onto the next area. While Vince McMahon Jnr's WWF put the territories out of business, the NWA and then WCW still maintained the heel champion dynamic with the babyfaces only getting short reigns.
As to the question asked, the wrestling model has changed from Flair's pomp. Televised world title matches generally only happened at PPVs (with free TV used to build the feud for the belt) and while there was the occasional 'house show' title change, these were few and far between. Today, on top of 13 PPVs per year, we have also only returned to one world champ in the WWe very recently and world title bouts on RAW and SD over the years have been quite plentiful.
As such, I don't mind multiple reigns and don't think numbers really matter. What defines a wrestler's legacy is the character. We've had many multiple time world champions whose legacies will be forgotten in ten years while guys like Roddy Piper, Ted DiBiase and Arn Anderson will still be remembered.