Comment by dmitrygr

Any country can reject non-citizen entry, for any reason or no reason at all. In fact, part of a definition of a country is ability to practice control over its territory and who is and is not there. This necessarily includes border controls, which any country can decide to make as onerous as they please. No non-citizen of a country has any right to be present in it, except as permitted by its government, so any country if free to make it as hard as they wish to enter for non-citizens. This may not be a good idea, but control over a territory is literally part of the definition.