Going fast and having just a front brake can easily cause you to do a forward flip. 80% of your stopping power is in the front brake, but if you're going very fast engaging the front brake for an emergency stop can make a bad situation worse.

That's a pretty sad story there, I read a bit on his site and he seems to have been a very nice and knowledgeable guy. I'm pretty sure he would have smiled at the way you characterised him, there are worse things that people could say about you after you die.

For an analogue, you can drive in traffic with a car and never touch the brakes, if you're a really good driver and you plan ahead. So, in theory you could remove your brakes and still be safe.

So, now for the obligatory 'think of the children' argument, but it could just as easy be the think of other people in traffic that do unexpected stuff or the mistakes that you yourself might make (nobody is infallible):

Until the day that that toddler walks out in front of you. And then, whether you're in a car or on a bike doing a good clip you're going to be very happy that you have all the stopping power that you could possibly want.

Now a clever counter argument would be that a freewheel cycle with discs on front and rear wheels would offer less stopping power than a fixed gear cycle similarly equipped.

As for bike styles, I have a recumbent (a Zephyr) for fast touring on bike trails but I'd never ever take it in to traffic with vehicles around me (too low), also it has a very large bell on it (and I don't care if people think it's gay), because people are simply not used to bikes doing that sort of speed.

I've never bought the front brake argument. As a bicyclist, motorcyclist, and physicist, I know that 100% of your stopping power is on the front brake, exactly because (as you say) the front brake can make you do a forward flip. This means that all your weight is on the front wheel, and the only thing you can do with your rear brake is make the rear wheel lose traction, and that will indeed make a bad situation worse.

The answer is to become proficient in the use of your front brake and commit the proper brake pressure to muscle memory so that you do not grab at it and skip the front wheel before weight has shifted, or do a "stoppie". Practice maximum braking from speed, it could save your life!

There is one counter-argument to this: In situations with poor traction (on snow, ice, sand, etc.) you don't have enough traction to shift all your weight to the front. In those cases, the optimal case is judicious use of both brakes. But if you bike on such surfaces, you have much more to learn anyway...

Second lesson: People rely too much on brakes. In most high-speed situations, swerving is a better action. (Due to the way braking distance vs turning distance scales with speed.) Practice change direction quickly to avoid obstacles in your path!

Sorry for the long post, but it was fresh in my mind: My wife got side swiped by a car turning right yesterday. She's fine, but we had a long discussion about bicycle proficiency and the futility of being "dead right".

I went ass-over-teakettle once on a tenspeed in Amsterdam traffic, I was very much in a hurry (trying to catch the train to work) and rode faster than the car traffic, a guy turned right into my 'lane' and I hit the front brake in a reflex. Too hard, I flipped right over and bounced off the pavement after doing a salto. Bad scrapes everywhere, fortunately nothing more serious than that (I used to be made of elastic, if I tried that today I'd be dead). I never realised that you could do that until it happened.

I was 'right' too, but since swerving wasn't an option and my front brake worked a bit better than expected I wonder if there would have been a better way to handle this (sliding sideways for instance). Accidents lurk in remarkably small corners. My nightmare scenario for a fixed gear cycle would be downhill at a good speed with a sudden obstruction. That would be the 'perfect storm'.

Glad to hear your wife is fine, bicyclists are on the bad side of any close encounters of the third kind with other traffic.

It's easy to get tossed on any bike with an aggressive geometry if you are going fast and slam the front brake. Personally, I do not think the most popular bike styles in the USA have the right geometry for commuting in the city. The default accident for stopping abruptly should not be flying over the handlebars, which is what happens on road/track frames and MTB frames. My bikes are set up more like dutch bikes or beach cruisers, which have a very upright geometry with my bodyweight over the back wheel.