Playing a draw at home is not always considered bad if Arsenal can provide a better game in the second leg (away match). Of course, Bayern Munich will likely be the favorite at home, but Arsenal is a good team who will most likely also win the second leg.
Manchester City and Arsenal both ended the first leg of the Champions League quarter-finals with a draw. They have good form to hope for a ticket to the semifinals, but Real Madrid and Bayern Munich also have the same chance in the second leg. This match will be very interesting of course, that's because all four teams still have a chance.
From this match it was clear that Arsenal dominated the game and they also managed to score the first score. Actually, if we look at Arsenal's performance then victory is in sight. Luckily, Bayern Munich got a penalty kick so they managed to make the result end in a draw. If Bayern Munich didn't managed to take advantage of this opportunity, Arsenal emerged as the winners. I am sure that in the second leg Arsenal will use their full strength to snatch victory from Bayern Munich.
I doubt that Arsenal can win this round, indeed both teams still have the same chance, but in the next match Arsenal will face Munich away, of course this will make Arsenal feel pressured and I'm not sure that even if Arsenal uses all their strength, Munich will also do the same thing, let alone competing at home will make Munich more confident to win.
Because it is an away match for Arsenal, I don't see Arsenal becoming less in their attacks against Bayern Munich. Arsenal will be attacking Bayern Munich with their full strength and if Bayern Munich doesn't have their defense strong built, they will lose to Arsenal team. Arsenal really don't have the mindset of performing less because of they are the away team.
Champions league this season doesn't care about that the team(away or home) that takes victory. It is let the best perform team to win.