Why worry about "danger zone" when thawing meat if I'm going to be cooking the meat immediately after?
If I am defrosting meat in order to cook it, and I am cooking at safe temperatures, then why should I worry about how I defrost my meat?

If this were true, wouldn't it then follow that it would be safe to cook meat which has already spoiled, so long as you cooked it at a safe temperature?  It's not true.  While the bacteria would be killed by cooking at a safe temperature, but the toxins they leave behind remain and can make you ill.