We won't be title contenders as long as Wenger is around, as we all knew before today.
He has a romantic idea of how to run a football club - stay loyal to your players, build team spirit, pay everybody well, give young players time even if you know it will hurt you, don't buy in the market if you think a player already on the squad could do almost as well with some maturation, etc. He is a very admirable human being, sort of like a stock character in an inspirational movie about a football club that overcame the odds to win things the right way, staying true to their values, etc.
Unfortunately, its not a movie. Football at the top level needs to be a cutthroat business and Wenger doesn't have it in him to manage the club that way. Ultimately, this leads to things like having your two best players poised to leave for free because you haven't bought anybody else nearly at their level since you brought them in, starting two LBs in a three man defense even though only one CB is completely unavailable to you, having a LWB who can't cross with his left foot because you're trying to shoehorn both Bellerin and Ox into the team, and relying upon a player like Danny Welbeck as your first choice backup to Alexis.