Regardless of which type and how tough your door is, if you are not using it properly, then it is bound to lose its beauty and functionality along the way. It would be senseless to get something like shaker doors for your interior but not handle them with care. Some practices may be obviously damaging, however, there are common ones that most do not even suspect.
If you have the tendency to pull the knobs of the door while closing, then you might be compromising its entire structure as well as the knob itself. Uberdoors.com says it is always better to twist the door handle and keep the closing silent. A little bit of effort is better than having to repair the door sooner or later.
Putting a little bit of weight
Whether it be a harmless prank of something resting on top of the door or making the knobs a hook for hanging the bag, you are slowly destroying the hinges. Remember, the door itself is heavy, adding weight to it will increase the chances of it falling off. Along the way, you might observe that the topmost edge is hitting the frame when closing, that is already a sign of the consequence.
Most think that doors are indestructible, that banging it won't make much of a difference, however, after a few repetitions, you may slowly start to observe cracks. This is prominent for hardwood. For PVC and other softer types of material, you will observe chippings along with the cracks.
Anything that is used beyond its limits is bound to fail much earlier than claimed. Regardless how tough a material will be, you might be looking at an earlier repair or replacement. Remember, there is no such thing as tough if the conditions it is exposed are beyond the norm.