It's not about skill, it's about willingness to learn the language. It's about people not caring to learn the language and choosing to not be able to communicate with the people around them (except for that small bubble of their friends and the wait staff they expect to adapt to them).

That willful ignorance to anything around you is typically not limited to learning the language, and I agree that it seems to be at the core of Berlin's identity. Berliners love it. I loathe it, and I'd prefer not to send money to Berlin each year so they can continue in their ways.