Why aren't static methods considered good OO practice?

Static methods cause tight coupling, which is a violation of good Object Oriented Design. The tight coupling of the calling code and the code within the static method cannot be avoided through Dependency Inversion because static methods inherently don't support object-oriented design techniques such as Inheritance and Polymorphism.

Besides static methods are difficult to test because of these tightly-coupled dependencies, which oftentimes lead to third-party infrastructure that the code depends upon - like a database, and it makes it very difficult to change the behavior without actually going in and changing the code.

Static methods aren't considered good OO practice due to below reasons:

1) Prevents from Re-usability:

Static methods can't be overriden. It can't be used to in interface.

2) Object Lifetime is very long:

Static methods remain in the memory for a log time and its garbage collection takes long time. Developer's don't have control on destroying or creating of Static variables. Excessive usage of static variables can result in the memory overflow.

3) Also, some other points:

It doesn't respect the encapsulation because object does't remain in the complete control of its state. It doesn't follow concepts like Inversion of control, loose coupling, dependency injection, etc.