Many chemicals both in the detergents and possibly in water can cause damages to the machine. There are some other problems like hosepipes or other fittings getting loosened in the course of time. Improper electrical connections can also cause damages to the machine. No one can predict the problems that may occur due to moisture, heat, chemicals and electricity. Overloading of clothes also can cause damage to the machine.
Those that want to consider the environmental impact can go "green" with a miniature hand-operated version. They are inexpensive and use very little soap and water, and no electricity. If you want the absolute king of the hill when it comes to engineering and performance, treat yourself a Miele washing machine.