Because Arsenal is at away the reason you said the club has bad result with Bayern Munich? Do not forget that Bayern is not also a small club and it is in the second top position in Bundesliga this season. Did you watched the match? I think Arsenal tried. It is true that it is possible that Bayern may become stronger at home and the club might win Arsenal. But about EPL, as Arsenal has chance not to be the winner, but it also has the chance to win the EPL this season. I hope Arsenal will not disappoint again in this season.
I think no matter how serious a team is in their prime, their will come a time when they will fall out from their place. Bayern might be bigger but are they really that big like before when they use to take Bundesliga title like water, those are in the past glory. Now, Arsenal is the real deal and they are in better position this season and the last, so expect a Comparism with even the top teams from other leagues because they have done the impossible that even Arteta wasn't sure of making for the club.
The only thing I can say that I'm not satisfied is allowing Bayern to make goals in Emirate, it's going to be a hard time for Arsenal to recover in the second but if they eventually don't, we have another season next year and if they win the Premier League title, we will still celebrate because breaking a bond of 16 years without Premier League trophy is a bad record.