Wrestling is inherently fun. Really fun. Little kids spontaneously wrestle for pure enjoyment, and that's not something you necessarily lose as you get older, particularly if you keep doing it.
At a certain point, people tend to get more competitive about it. If you decide you really like it, you'll probably get a desire to become good at it. So you start working at it. This process, which isn't specific to wrestling, is part of what we call "growing up".
There's a tendency to see the benefits of hard work, and think that if you could weed out everything else, and just work hard all the time, you'd be the best at whatever you're doing. I think that tends to be a mistake on a couple of accounts.
First, we're human (which is what makes this interesting). Humans tend not to function well when you take all the pleasure out of things. You have to find a balance that works for you.
Second, there are things we learn through play that we tend not to learn when we work. We're more open to experimentation when we play, and we usually have more time to consider the results.
When I started coaching, I stopped riding legs. I was working with high school kids, and throwing legs in was boring and unproductive; it'd take a couple of seconds to squash them flat, and then there was no wrestling going on... just me looking for a turn. So I started doing other stuff... some of it semi-random. If the kid scored, good! That's who you're trying to make better, after all.
In the first few years, I learned things I hadn't picked up in 20 years as an active wrestler; I'm far better than I was in college. And as a bonus, that sort of messing around isn't hard on your body. When you're training seriously, it helps to have ways to make progress which don't take a toll on you, because a lot of the other things you're doing will.
The atmosphere off the mat matters, too. We played a few paintball games when I was as Iowa, for instance (the most memorable part of which was watching McIlravy perform crazy movie stunts, like jumping off of high things and shooting at people while falling upside-down). I never went into for the high-stakes rock-paper-scissors tournaments, which featured video review, but they were popular. And then you had the alligator wrestling road trips, questionable home improvement chainsaw techniques, and hunting (usually in appropriate places[/i]).
Just so you know that wrestling under Gable wasn't chewing on rocks every day. It wasn't a barrel of monkeys, but people liked being there, and were into what they were doing.
I expect Cael is striking a balance which works. It can't be all fun, and I don't think he'd claim that it was. But fun has a place in wrestling, and a positive attitude about hard work rounds it out.