Using the front vs. rear is all a question of where the traction is. What I’m claiming is that there is more traction in your front wheel than you think during MOST wet riding. Moreover, both you and I have tiny weenie crappy rear brakes. If I were to stop using only the rear brake, it would take me about 4-5x as long. So even in the wet, I still clamp hard on the front when I’m straight-up-and-down. Yes, I use the rear brake too, but on my bikes, the rear is too weak to do much. I’d be dead without the front.
You’re right, however: there are special conditions in which the risk of losing traction in one wheel is greater and so more caution should be used. You cite off-road riding as an extreme (but good) example of this, and while it may be too different to be applicable to the road, it is a good example of how super-low traction conditions are a safer place for rear slides and much more punishing to front skids. It’s simply a question of when you choose to alter your braking bias. For me, it’s almost never. I’ll be careful using the front on a manhole cover, a sewer grate, some slick-looking paint, wet leaves, etc. but if I know that might be in my future (i.e. if I’m riding blind turns and can’t see ahead, or if I know the road hazards ahead, etc.), I will have already reduced my speed to compensate for my not being able to stop worth sh%&. If you’re going 50mph, you better be able to use the front brake, because the rear isn’t going to stop you before hell freezes over.
You’re right: riding on the street is about maximizing your margin of safety. Which is why I’m a big pussy on the street (as we’ve discussed earlier in this thread). I don’t advocate knowing how to get 99% braking potential from your brakes because I need that on a regular basis. On the contrary, maximizing your margin of safety starts with, as you said, judgement, the use of which controls the speed you are traveling such that you will be less likely to put yourself at risk. If you were not going so fast, and you were not taken by surprise by a light turning yellow, and you had practiced braking more under a wider variety of conditions and instinctively balanced your braking approach without having to think, you would not have failed to brake before the intersection.
These are all things that come with practice, both of judgement and motorcycle skills. I’m no master of this stuff, and I’ve only been riding for a few years, so I’m not going to pretend I have this down at all. But I will say this: you know riding is more dangerous than driving by far, and in the end, it is not just judgement that will save your ass, but judgement combined with reflex, optimal, and instantaneous reactions that will protect you from the unexpected things that come up in riding. No, it’s not about being able to brake from 120mph-0mph as fast as possible and regularly exercising that ability on the street. It’s about having the skills to get your bike to obey you, but using judgement to avoid having to use them until something inevitably crops up to try to kill you. And it will happen.