That's not entirely true. Check out this quote from Greg Glassman in
Girevik Magazine:
This is almost certainly hyperbole and having done both a good deal of CrossFit and some Starting Strength, I can attest to the fact that you are not going to magically pull 500 (let alone 750) pounds off the ground by just doing the main site WODs. This is especially true if you start off with a 1 RM of 200 lbs.
So, CrossFit has made at least one claim about being a strength program. I think Coach Glassman's statement above would not hold up well under scrutiny and I would really like to see any evidence that someone came to CF with a 200 lb deadlift and two years later could pull 500 lbs without doing something along the lines of Starting Strength/Practical Programming.