Physics does have something to do with it. It takes less energy to leave a food plate on your night stand than to get up and bring it to the sink. It takes less energy to throw your clothes in a mess on a chair than to fold them and put them away. Then when you eventually clean everything up, you expend less energy than the sum of energies that it would have taken to keep it tidy. For example, you can make 1 trip with 4-5 plates and cups to put them away as opposed to 1 trip per item. So you turn an energy profit. Messiness is energy expenditure minimization.

You might ask why clean up at all. For most people there comes a time when the mess starts being distracting and once they start having to look for items, they start to expend more energy per action. So it makes sense to clean everything up and start over.