I'll put this here just for you to have a watch. I'm not trying to argue or anything, we are all entitled to our own opinions and obviously they differ.
I'm sure there are plenty of books and videos that have a counter argument but you cant argue with the fact that using a conventional braking technique in a 30mph hair pin (as in off the brakes and back on the throttle), the bike goes down (unless your a very competent rider and dont panic) where as using trail braking he was able to enter at 70mph and easily make it round. He even says he almost found it impossible to bin the bike.
Also worth noting that this was with ABS switched off.
Like I say I'm not trying to argue with anyone I'm just displaying the info from my point of view :-)
I don't think we're arguing Dude, but it's how we're hearing/interpreting what is said in the video - my take on what was said is slightly different to yours in a couple of key areas - all down to our differing views on the context of the video. My view is that he's using this to demonstrate that when encountering an unexpected issue/obstruction mid-corner, it is possible to trail-brake safely when leaned over, when done properly, to help avoid a crash and hopefully the following comments explain how context can create different "understandings" - must admit this is why I prefer to do classes where you have the opportunity to discuss comments and techniques with the instructors, to make sure the context is clear.
At the beginning, Chris chooses to go into the hairpin at 30mph - it's not the fastest he can go in, or the fastest he can go around the corner using his normal approach - it's just an arbitrary speed to demonstrate the point and he does the typical type of trail braking that happens with an average rider on the road, to see how easy it is to get it wrong (very easy, it seems) - he doesn't follow the "brake before you turn" approach to get the right speed for the corner, he just deliberately brakes hard mid corner at that speed (visible by the way the forks dip before the front tyre breaks away) - and he crashes, or would do if the bike didn't have outriggers.
When he tries to trail-brake "properly", he deliberately goes into the corner much faster and by finding the traction limits by pushing the bike/tyres to their limits, with the benefit of outriggers, he ultimately finds out he can get round the corner at the 70mph speed, but only after a lot of front wheel tucks, which on a normal bike would all have been crashes.
Nowhere does he say that 30 mph is the fastest he can get round the corner using his normal riding technique, nor does he say he couldn't go even faster using trail braking (he probably could) - the speeds were chosen to demonstrate the different outcomes between "normal" rider trail-braking and the outcome after you've had the opportunity to practice it a lot on a bike you can't crash.
At the end of the video he quite clearly says that unless you are smooth on the brakes and know exactly what you are doing (and basically are an "expert) "stay away from it, you do not want to brake in the middle of a turn". He also says "don't try this at home" - he had the benefit of the outriggers to save him and the bike, and no oncoming traffic.
The key point I took away from this video was that Chris was saying that IF you encounter a problem during a turn, you'd be surprised how much you CAN brake while leaned over, if you brake gently and skilfully and it CAN be a useful skill to master, but under normal circumstances I take on board his final warning "don't try this at home".
After watching that video, I'm tempted to find a school which has outrigger bikes to try and practice the technique, but on normal roads, with debris, changing road surfaces and grip levels, rain etc, I'd keep it as an emergency tool/skill.