That's y i said that it's not a must but a good to have thing... other solution could be to have simple knee and elbow protection... and that could be found in any reasonable sports shop at a very low price... 
Regarding leather jacket, that's y i opted for a cordura jacket because in our country mostly the temperature is hot... :S
But still i think it would be wearable by you when we enter the areas at greater altitude but not sure about that... 