Good results are quite often followed by good performances. Actually, it's happening in most of the games, teams that perform better generally win their games.
You problem is that you only see parts of those performances that you like and think that was great performance all around, and ignore the fact that only 5 teams conceeded more goals than Germany at this World Cup. Which frankly, is horrible stat that shows that your manager didn't really have a clue how to set up his team defensively against teams he was supposed to attack, considering you conceeded 2 goals against Japan who are clueless up front, and you even conceeded 2 against Costa Rica(who scored 3 goals in total). You say good tactically but then you lose against Japan after leading the game, how exactly is that good tactically?
Being stubborn and arrogant in thier views, hence very unlikeable is the feature many german fans here have in common here for some reason, some of you think only your way of playing/watching football is the correct one, and anyone who doesn't agree with that is clueless or doesn't understand football. Reminds me of one Barca fan who said that Barcelona never had a poor game in their modern history, because they always play the correct way(tiki taka way). Fair to say is that no one liked him either.