Doesn't Default in Java 8 destroy the whole idea of not allowing us to do multiple inheritance? [duplicate]

This question already has an answer here:

• How does Java 8' new default interface model works (incl. diamond, multiple inheritance, and precedence)? 2 answers

Can someone help me understand why they would add Default in Java 8 to allow implementation to interfaces instead of just allowing us to have multiple inheritance in abstract classes? What exactly is the difference between just allowing us to extend multiple classes verses allowing us to create Default methods in interfaces?