I think the problem is that a lot of people do not know how long is too long. We have to get real here. There are a lot of things to consider before saying that an airhead cannot sit at idle for a few minutes. And we have to use some common sense. Sure, sitting at idle is going to allow the engine to build up heat. That is expected. Does that mean that we have to turn the engine off at every stop light? No. These engines were designed to be ridden in normal every day traffic. That includes sitting at idle for short periods of time.
Yes, the reason for the engine failure is due to overheating and the oil not being able to lubricate properly. So to help eleviate that problem, make sure you do proper maintenance. Change that oil and filter on a regular basis. And use a top quality oil that is rated for the application. If you have to commute thru heavy traffic with stop and go situations, change the oil more often. Maybe install an oil cooler. Or if all that will not work for you, commute on a different bike.
There are lots of us who have gotten well over 200,000 miles out of our engines without major rebuilds or breakdowns. And we ride the bikes as they were originally intended. Don't over load them and do proper maintenance. And learn to use the upper end of the tachometer. Get those revs up and let the oil circulate.