I think the reason why Chelsea have gotten more attention from the media concerning their performances this season when compared to their city neighbors Arsenal is because they started better than Arsenal and were been considered by many as a serious contender for the English Premier League title this season.
That said, I totally understand your opinion about Arsenal and why we should also talk about their inconsistency. Arsenal who finished in the 2nd  position of the league table in the last two seasons at the start of the season were expected to be one of the major contenders for the league title but surprisingly, Mikel Arteta's men have been too inconsistent. At the moment, I don't consider either of Chelsea or Arsenal as a team that's strong enough to challenge Liverpool for the league title this season so I think it's going to be an easy ride for Liverpool to win the league since reigning champions Manchester City is also having a poor campaign