Let's give them one more season before you draw your conclusion. Arteta have bought good and quality players this summer, and I believe that will change the whole mentality of the team. With the current set of players, Arsenal has the highest advantage to win EPL next season, because they have finished three consecutive seasons as runner up. It shows that they have the experience and players to win the title next season.
For upcoming season, their are six new IN's for Arsenal. Arsenal will be fully fired up to win next season after finishing as runner up in last three consecutive seasons. Their is nothing wrong with Arsenal squad as they have best players available in playing 11. The only problem with Arsenal is losing the track just before the finishing line and this is the area where team coach and other managing staff need to work on. Otherwise club will continue to spend huge money on players with no fruitful results.