I do not disagree that weight and balance is extremely important. That is why I was suggesting that extremely reliable technology, aircraft quality, is available as a final check. Part of my job has been accident investigation, and a lot of my training has been from the aviation industry because crashes get the most intense investigation. You must be aware that many incidents have occurred because planes were improperly loaded.
Still for the main part passengers on large jets are loaded by standard passenger weight. Yes, the standard passenger varies by time of the year, and has grown over the ages, but they aren't weighed. Back in the 80's when I was commuting quite regularly on Metroliners, I would pay more attention to the passengers emplaning with me. Were they all 200+ pounders like me, or a mixed lot? Much more significant when there were only 16 passengers (my commute was always weight limited so we never flew with a full 19 passenger load on my commute.
As for my reference on heavy equipment, it is much more important than you suggest. Tires are the critical factor. The tires are supposed to be inflated with nitrogen but almost all customers inflate with air. Air contains - oxygen. Now think of the size of a tire filled with compressed air - lots of oxygen. Tires are made with flammable materials that tend to deteriorate inside. So we have oxygen, a highly combustable material, all we need is heat for an explosion. Overload, then transport. It is not as simple as you say - sluggish performance. The minimum safety range we say to stay away from an operating truck is 100 meters, but I've located the pieces a lot further from a tire explosion than that. So aircraft are not the only vehicles for which weight and balance are important. Its must that failure to pay attention make for bigger headlines because of the number of people killed per mistake.