Gotta be honest, watching the first episode I had the same feelings as you - these guys don't seem very focused. And I know the players are going to joke around and have a little fun, but to your point, probably during drills isn't the best time.
What got me even more was the jokey nature of the staff. They're all just having fun, joking around, getting yelled at by players, and generally not acting as leaders (though again, this is just 60 minutes in a week). Hue Jackson's continual smack talk to the D is going to get that little Giovani killed (seemed like the D was teeing off on him to get back at Hue.
I just see Marrone and staff acting the same way - way too focused on Football.
Regardless, I love Hard Knocks, it really makes you think about what a crazy business and game Football is. The guy getting hurt at the end was brutal for him, poor kid...