Rousey and Mcmann were fighting an MMA fight, not wrestling. The threat of being punched in the face changes everything.
Moot point to bring that up.
Judo doesn't win you fights, sure, it can put you in some advantageous spots, but it's not on the checklist for MMA training. You're not deciding on judo over any one of the three 'staples' you must have to be a complete fighter.
Chael isn't wrong through and through here.
What are the three staples according to you? I see it as:
Standup (punches, kicks, knees, elbows, striking defense and evasion, footwork)
Clinch (takedowns, throws, sweeps, takedown defense, strikes from the clinch, pull guard, control in clinch, thai plumb)
Groundfighting (positioning, top control, bottom control, passes, reversals, sweeps, escapes, submissions, submission defense)
If I had to make it into sports, the main ones would be:
Standup: Kickboxing (western or K1/Dutch style), Muay Thai, western boxing, karate
Clinch: Freestyle wrestling, Greco-Roman wrestling, Judo/traditional Jiujitsu, Muay Thai
Groundfighting: Wrestling (freestyle/greco), Judo/traditional Jiujitsu, BJJ, catch wrestling, Sambo (Sambo is like a lighter version of MMA, but has a heavy base on leg locks you don't see often in the other ones)
It has pretty much been proven in my opinion that the best base for MMA is wrestling, because usually it means you control whether the fight stays standing or on the ground and you are good at controlling opponents and positioning on the ground. Also, wrestlers are used to grind and often times physically strong and hard punchers (even when lacking technique). Judo comes in second as a grappling sport, but would definitely not deem it useless. It is similar in wrestling in all the above mentioned aspects, only that they have a Gi and in MMA you don't. But then you have more submissions than in wrestling and the element of surprise in some of the throws that you don't see in wrestling (gives you an advantage a la Machida or Wonderboy because your opponents are not used to those techniques, especially at such a high level). The new rules in Judo though, of the last 12 years or so, definitely messed up the sport a bit, making it essentially Greco with a jacket. I think this is why Chael calls it useless.. Rousey is still of the old guard though by the way, she is used to leg grabs etc. I still hang on to the old Judo rules in my head, still can't comprehend that they ruined the sport..