Behind closed doors, people say "on the one hand, this is the hardest place in the developed world to start a business. On the other hand, if you manage to get something running in Germany, it will run everywhere."
But that's a process and when you've done it once it's just copy&paste for every n+1. Or you get an accountant to do it for you, which is apparently 50Euros/employee/year for all the paperwork.
Other than that it takes about half a day to register a business. Despite what people say, you'll always get by without /any/ paperwork if you don't have employees or revenue.
If there's anything missing in Berlin I'd say it's a really good university. Today's Silicon Valley survives on its symbiosis with Stanford. Before that, XeroX and a few other labs were probably nurturing, plus the hippie spirit of the 60ies that encouraged people to hang out and "do cool stuff".
Berlin does't have that industrial base because it was isolated for 40 years, causing large companies (i. e. Siemens) to leave. It's creating a good community but it's missing the exceptional people that can catalyze real innovation.