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.
