I checked the statistics between Bayern Munich vs Mönchengladbach, i found out that in the last seven years Monchengladbach has being a pain in the ass for Bayern Munich. I was not surprised when i saw both teams performances and the game having just one goal. I think even the coach wasn't really impressed with his team scoring only one goal.
Bayern Munich only needs to win and get three points in each match even though it is only by one goal. Because for now Bayern Munich's rivals still have a point gap with Munich so Munich only needs to win to maintain it so that they stay at the top of the Bundesliga standings. But if one day Munich's points are the same as other rivals, of course Munich must be able to win with more goals so that their number of goals can be more than other teams and that will keep Munich in the top ranking even though the number of points is the same.