You are cooking them too hot and too long. The pan is too big for the amount of eggs, giving you a thin layer that will overcook quickly.
I make scrambled eggs over medium or lower heat. I break them in the pan and then gently break up the yolks and mix in, then scrape them up in big flaps from the bottom as they start to cook and scrape, fold, and move them gently, turn them over if needed as they set on the bottom. One key here: TURN OFF THE HEAT BEFORE THEY ARE DONE, turn the eggs over and let them gently finish cooking to the degree you want. Still moist or rock hard--your call and they shouldn't burn!
If you whip them up, the air in them makes them more likely to overcook on the bottom. I don't add water or milk to them, just the eggs. Using this technique it is easy to get them to the degree of doneness you want, and they have a great texture.