da könnte ja jeder kommen (then everony tries that, very loosely translated)
1. Das haben wir schon immer so gemacht (that's how we've always done it)
2. Das haben wir noch nie so gemacht (we have never done it like that)
3. Da könnte ja jeder kommen (then everyone would try it)
They're so German that they're very difficult to faithfully translate. Just imagine a grumpy older guy looking for every excuse not to do what you want him to.
“Wo kämen wir denn da hin?“ (Just think where this would lead to.)