So, chances are, he's going to be happy in whatever outfit he joins. And he's going to think his outfit is better than the rest. Just what happens. Unfortunately you can't get an idea of outfit culture until you're in it. And while some outfits can maintain a good (or bad) culture for years, some can change substantially within 1-2 years. And even the outfits with a bad culture have produced great military officers and cadet leaders, and the outfits with great cultures have produced poor ones.
Regarding an all male outfit or not, I was also told the same thing regarding joining an all male one by cadets in K2. And I was on the fence till my New Student Conference. Ultimately I chose an integrated one. And while it is true that we probably did less, what one may call bonding experiences, and someone else may call "gay" stuff, I feel like I am happy with my choice. But I also had really good female buddies (the ones that weren't good quit by the end of fish year, sophomore year at the latest, or transferred to other units). We all held each other to a high standard. And there probably was some more drama here and there, but we figured it out.
The biggest issue I have with the all-male outfits is how they (back when I was there) treated female cadets from other outfits. Like they treat them like crap. Some would refuse to take their whip outs, some would push them out of the way in the chow line, call them names in common areas, etc. I don't understand how a man can treat a woman like that, especially at a school that espouses traditional and conservative values. Not to mention, these people will be one day leading females in the military (or civilian world), or be led by higher ranking females.
That's not to say that there weren't good guys in those outfits. I know many that were great people, didn't participate in that kind of stuff. But that is not something I would think should be considered acceptable. And maybe times have changed, and that isn't as common. I don't know.
Also, anyone that is more than 4 years removed from the Corps has no idea what their outfit is like anymore. Unit culture shifts a lot. If I told you my outfit, which was really good when I was there, is still a great option, I'd be lying.