I tell practically everyone I know to try Crossfit. There are two basic difficulties with any exercise regimen, and Crossfit nails both:
1. Figuring out what to do.
2. Actually doing it, consistently, over the long haul.
Crossfit will teach you how to do the old-school, badass basics of fitness--stuff that will get you in great shape and is actually fun to do. No gimmicks, no miracles, just stuff that will kick your ass.
Doing Crossfit also makes you a member of an incredibly friendly, supportive community. This makes it so much easier to stick with it--every class, you'll see people in your community, friends, going hard and making progress. You support them and they support you. You'll work out with beginners, who you can help, and with badasses, who can help you.
Crossfit seems to be for people who are already pretty strong athletes. Is it really something you can just jump on board with if you're fairly out of shape?
I've spent the last few months following the "Starting Strength" plan (http://startingstrength.com/) with the idea of getting in good enough shape to do crossfit.
You absolutely can go to Crossfit if you're out of shape. It requires a certain disregard for your social instincts, because you will feel out of place. While I was taking on-ramp classes (intro classes with more intense instruction and slightly easier workouts) I saw several extremely overweight people join up. I didn't see any of them more than a few times, but they were welcome and could have kept with it if they wanted to.
It's easy to feel self-conscious and unwelcome. Half the people in my on-ramp classes were in stellar shape already, and at least two of them were professional personal trainers who were interested in eventually becoming instructors. There were times when I was sure nobody else wanted me there, and I kept going just out of sheer bloody-mindedness, with a kind of "fuck 'em, I don't care, I'm going anyway" attitude. In retrospect, it was all in my mind. I never minded any of the people who were in worse shape than me. You won't be in anybody's way. And I would have said all that to someone who hadn't been doing "Starting Strength" for a few months, so it goes triple for you.
I think Crossfit is great for beginners. Most of the exercises and workouts scale very nicely, so you don't need to be fit when you start. For example, a workout might call for 100 push-ups over the course of 20 minutes. If you can't do strict push-ups, you can do them on your knees. If that's still too hard, you can do push-ups with your hands on a raised surface or even against the wall. Similarly, if the recommended weight for something is 135 pounds, no one will look down on you for using 85 pounds or 25 pounds if that's where you're at. The important things are that you come consistently and work to the best of your ability. Everything else will take care of itself, regardless of your starting level.
It definitely helps to have a good athletic background, but Crossfit does an amazing job of welcoming beginners. Honestly, I can't think of any other community that does such a good job of simultaneously pushing the most advanced to their limits while still welcoming beginners.
Most Crossfit affiliates have an on-ramp program that will get you, no matter where you're starting, to the point where you can participate in full workouts.
It's also a bit ironic that starting strength will teach him the proper mechanics for most compound lifts, and then Crossfit will turn around and teach him how to work as quickly as possible with an often times alarming disregard for form.
If anything, I'd look into barbell complexes as a way to prepare for Crossfit.
Your statement about CrossFit encouraging a lack of proper form is patently false. That is a common, and false, criticism of a great fitness program.
CrossFit encourages you to work fast because intensity is correlated with power and results. Power -- what we want to build a capacity for -- is simply work over time. Results come more quickly to intense training because the body has shown to adapt faster to (relatively) intense stimuli. crossfit.com is covered in references for the interested.
Form is a key part of these movements, but learning a proper squat or clean is the endeavor of a lifetime. No one is perfect at significant load here. CrossFit teaches a balance of these elements that maximizes fitness in the athletes. Injury due to improper form or overtraining is contrary to what CrossFit wants to achieve.
Some people take things too far. Some people not far enough. CrossFit simply wants you to push your relative limits each time you do a WOD. That is how you get better. You're never going to be a great race car driver taking practice laps at 30mph.
There is more to say, but I'd challenge you to find a good affiliate and try it out. Experience is a grand teacher.
In my experience, Crossfit trainers are good at coaching form. Their top priority is getting you to do the movement and get a good workout, but when somebody has bad form, they coach them a lot and make sure they use light weights or no weights at all until their form is good enough to lift safely. I always had terrible deadlift form and wasn't able to correct it until I got some coaching at Crossfit. They fixed me up quickly, got on my ass when I got sloppy, and within two months of starting, I was lifting more than my previous deadlift PR -- 45 times in a single workout. (Granted, my deadlift form was atrocious. I was squatting 40% more than I deadlifted and had basically given up on it before I went to Crossfit.)
The better your form, the more you can safely lift, and the more you can lift, the higher the work rate you can achieve. That's the logic that drives the Crossfit trainers I've worked with. Crossfit isn't consistent from location to location, though, so what you say may be true.
1. Figuring out what to do. 2. Actually doing it, consistently, over the long haul.
Crossfit will teach you how to do the old-school, badass basics of fitness--stuff that will get you in great shape and is actually fun to do. No gimmicks, no miracles, just stuff that will kick your ass.
Doing Crossfit also makes you a member of an incredibly friendly, supportive community. This makes it so much easier to stick with it--every class, you'll see people in your community, friends, going hard and making progress. You support them and they support you. You'll work out with beginners, who you can help, and with badasses, who can help you.
A well-run Crossfit gym is a magical place.