Why are Berliners so hostile?

I can't figure out what the reason is that Berliners are so... hostile and unpleasant. Here are three examples.

1. today: we (my wife, child and I) happen to be in front of the Asia Gourmet takeaway in Hauptbahnhof. We ask for two sets of 4 mini-spring rolls, not noticing that they come obligatorily with noodles. We ask the guy to remove the noodles, saying that we'll pay full price, as if we were buying the noodles (8 Euros). "Geht nicht," says the server. We insist (it costs him nothing! in fact, he saves money on this deal!), and he gives the spring rolls to us, but says nastily, "Nächstes mal, besser lesen." He could just as well have given the spring rolls to us without comment (or even, god forbid, with a smile), but no; there has to be a nasty comment accompanying the hand-over. The guy wasn't German, by the way, he was east Asian. This attitude is more of a feeling, a way of being, in Berlin. You live here long enough, you turn nasty.

2. Some months ago, Deutsche Bahn. My students and I get into the train from the first class side and are standing by the door. A conductor comes along and tells us to move to the second class compartment.  I don't mind that at all, except it's the way they talk. It's nasty and hostile, with an unspoken fuck you. What's the deal? Why is it so hard to say the same thing politely?

3. A year ago, a road-side ice cream shop near our apartment. We buy an ice cream for our son (then four), but we'd already bought two coffees for ourselves. Our son sits down at the chair outside the shop to eat, and we also sit with him. Suddenly the ice cream shop owner comes running out of his shop SHOUTING at us to get the hell out of his shop, because we bought our coffee elsewhere (he doesn't sell coffee). We say, OK, we'll stand outside the perimeter of the shop chairs (these are on the pavement), but he SHOUTS at us again to leave, we can't even stand there. Our son gets so upset he throws the uneaten ice cream into the garbage can and we leave. Wow. He could have asked us to leave POLITELY and WITHOUT SHOUTING AT US; but no,  of course, not. This is Berlin, after all.

I have experienced similar kinds of things in the US, Japan, and in India (but nothing like the shouting ice-cream man), but it's really about the frequency. India (rather, Delhi) is the worst of all places I know. But compared to the US and Japan, the level of unpleasantness in Berlin (Germany?) is amazingly high. Asia Gourmet is never getting me again as a customer, and I will abandon Deutsche Bahn---the Microsoft Windows of train travel---in a heartbeat if their monopoly on train travel is ever broken.  That ice-cream shop was never visited by us.  At this rate we'll have to stop going out of our apartment and order everything over amazon or something (duh: we'll have to deal with the DHL guy then).