Here are 3 reasons why:
Kitchens get dirty. Other than the usual house dust, there is often grease from cooking on the stove that gets on cabinets. The hand mixer is pulled out of the bowl too quickly causing dough to be thrown around, or you put something in the blender and the top pops off. It is much easier to wipe down a cabinet door that take off all the dishes from a shelf to clean and replace. Cabinets help keep your dishes clean.
All the same style dishes stacked nicely on a shelf can look good, but keeping that consistent takes effort. More often than not, the shelves hold misc dishes of all types placed randomly. It can easily become an area that draws the eye, but not in a good way. Cabinets keep a clean and consistent look in the kitchen.
Cabinets offer more storage. Especially in a smaller kitchen where you don’t want to give up storage. You can use shelf dividers to hold more items and use the whole interior of the cabinet. Shelves don’t offer you that option because it would look cluttered.
Before you decide which way to go for your kitchen, consider how you use your kitchen and what type of dishes you have. Are you willing to take the time to keep the shelves looking nice? Do you have enough additional storage space for all your kitchen items?