Gentrification is definitely happening in Berlin, people are not spraying new hipster startups with "Gentrification" or "Slave Fashion" for no reason. If you think rent is cheap now, it was astronomically cheaper just 5 years ago. Many businesses are taking venture capital money and coming here because as you said the rent is cheaper than San Francisco and those people have enough money they will pay much higher for rent than people who have lived here and know what you should be paying. You probably pay way more than you should.

My biggest problem with startup culture is the people though, they come to our hacker meetings and completely miss the point. They give presentations about their products or startups and advertise to us and are confused when people boo them or ask them really hard questions. A good example of this behavior: A friend of mine who was at the hackerspace noisebridge was working on a project, got a lot of attention near finishing it and was immediately asked "Where are you going to sell it?". That kind of thinking is what drove me here, because the community here is not libertarian hackers like you find at Defcon. And worst of all most of startup's products are junk, unnecessary, gimicky, or just (some popular company) + (some popular company).

The tech scene is here is amazing, probably the best in the world, I have met people here who are very smart. But its definitely not the reasons you describe. It is the hacker culture that exists here and has existed here since the 80's.