I think Coach is exaggerating somewhat when he says crossfit is better for putting on mass than bodybuilding workouts. I'm sure a properly designed program by Thibedeau or similar would put on mass faster than the WOD (especially the WOD's of a year ago and older). But mostly he's just attacking the isolation centric/only nature of mainstream bodybuilding. You'll probably agree that most effective bodybuilding (or any type of training) regimes starts with squats/deads/presses. But at that point they're not far off from Crossfit anyway.
His other arguement stems from the "neuroendecrine respone" brought about by all the full body high intensity workouts. I'm not sure exactly what that means - maybe J. Brown or others more heavily into crossfit can elaborate. Glassman claims that it mimics the effect of steroids on the body.
Also, I'd take issue that elite crossfiters are all smallish. Granted none of them are going to be hooge (especially considering they are probably eating strict zone and never have bulking/cutting cycles), but I'm sure there are many 6' 200lb crossfiters with <10% bf.
Video of "Crossfit Games" Some of these guys are pretty big imo.
Additionally crossfit doesn't mean only the WOD. I used to read the forums a lot, and many guys do strength/size focused programs with 3 powerlifting/o-lifting days a week, and 2-3 crossfit girls type workouts a week. One member AnthonyB is I think well over 200lbs and < 6', but he can still do Fran in 4 minutes or something.
As for it's claim to produce high performance I think the results from their competition this summer are pretty convincing. The guy that won had these results:
"Hopper Workout" - 13:39:
row 1000m
5 rounds of:
25 pullups
7 135lb push jerks
5k trail run - 20:45
Crossfit Total (sum of back squat, deadlift, standing shoulder press): 905lbs - probably broken down something like squat: 325, dl: 425, press: 160.
There are very very few people that could get anywhere close to all three results.
Josh Everett (Olympic lifter) did the hopper in 14:14, but had a total of 1133lbs - at a bw of < 190lbs that is strong no matter what your background.