surely a front wheel skid is more dangerous than back wheel skid regardless of where weight, centre of gravity is etc. I wuold rather my back wheel slip sideways than my front sliding out when braking.
In a way you are correct - unless you're an absolute genius, a front wheel slide is way more difficult/impossible to control/recover from.
Think about it this way - most modern cars (bear with me) have the brake bias about 60/40 front/rear. Assuming that you are travelling at a constant speed and press the brake pedal, the weight of the car continues to travel forward (momentum) even as the car slows. This compresses the front suspension and presses the nose of the car down, increasing traction through the front tyres.
As long as you brake progressively then the wheels won't lock and break traction, which is when the trouble starts, because a locked wheel is neither slowing you down, nor can it be steered. If this happens, the correct remedy is to release and reapply the brakes, "pumping" the brake pedal (cadence braking). This is essentially waht ABS does for you, it pumps the brakes very rapidly to prevent the wheels locking completely and allowing you to steer under hard braking.
Now look at a motorbike - a motorbike (with a few exceptions) has independent brakes. You operate the front with your right hand and the back with your right foot. You can stop a motorbike safely and quickly on a dry, non-slip surface by applying the front brake only, even if you really anchor on. Look at a modern sport/racing motorcycle - the front brakes are huge in comparison to the rear, often twin four- or six-pot calipers hauling on discs which are approaching 300mm diameter whilst the rear might be half that size with a measly single-pot caliper. All good motorcyclists know that all the braking is done on the front, in a straight line and bolt upright.
HOWEVER...If you are on a loose or slippery surface you need to adjust your braking technique accordingly. You need to give yourself longer to stop; and you need to adjust your bias accordingly (with a few exceptions you can't adjust the brake bias in a production car, which is why you need to leave longer and longer to stop as road conditions deteriorate).
For motorcycles, the police "Roadcraft" driving manual recommends 80/20 bias on a dry road; 60/40 in damp conditions; and 50/50 in wet or icy conditions, increasing braking distances accordingly.
Where am I going with this? Weeellll - personally I'm an advocate of using the front brake sparingly in off-road conditions, and the worse the conditions get, the less you should use it; BUT at the same time, good technique is just as important - grabbing a handful is asking for trouble; firm and progressive is where it's at and if you lock up, let go.