So, during my Java lessons we had a teacher who had a very special relationship with the language.
During the introduction he used to tell us that interfaces in Java are really poorly designed and that they would not reflect how an interface normally should be implemented. The possibility for a developer to add default methods to an interface or that a class could inherit from multiple interfaces was unacceptable to him.

Due to those reasons, he would hate on Java 8 and tell us to not use it and instead stay with Java 7 - dafuq!