Of course not , but Brighton beat Arsenal simply because Arsenal lost its guide - only them know what went wrong actually..
Arsenal fans deserve to be disappointed with the result they got when the team they support lost in a game dominated by Brighton and when they chose to leave the stadium before the final whistle sounded is proof I see they are really disappointed for what they have been supporting so far.
Likewise when Arsenal lost the next game when they lost 1-0 against Nottingham Forest. Arsenal showed their quality in the battle for the title at the end of the season.
Actually Arsenal fans have pinned high hopes on Arsenal this season when the Gunners topped the standings with a very promising game.
The mentality of players and coaches that they don't have makes them always end up with disappointing results.
Arteta can only be proud because he was able to bring Arsenal back into the UEFA Champions League after several seasons without experiencing how it was to play in the UEFA Champions League.