In languages which don't support "properties" (C++, Java) or require recompilation when changing fields to properties (C#), using get/set methods is easier to modify. For example, adding validation logic to a setFoo method will not require changing the public interface of a class.

In languages which support "real" properties (Python, Ruby, maybe Smalltalk?) there is no point to get/set methods.

In languages which don't support "properties" (C++, Java) or require recompilation of clients when changing fields to properties (C#), using get/set methods is easier to modify. For example, adding validation logic to a setFoo method will not require changing the public interface of a class.

In languages which support "real" properties (Python, Ruby, maybe Smalltalk?) there is no point to get/set methods.