Even though Bayer Leverkusen won the Bundesliga title last season and they are struggling to defend their title this season, I will not agree with you that Bayer Leverkusen is having a bad season just because they fail to be in the number one spot of the Bundesliga table this season. Bayer Leverkusen is an underdog in the Bundesliga league, and winning the Bundesliga title last doesn't make them the favorite to win it this season. Winning the Bundesliga title is Bayern Munich's birthright, and they will not allow Bayer Leverkusen to win the Bundesliga title again this season, so being in the second position in the Bundesliga table is not a bad season for Bayer Leverkusen.
You have made a really good point, except for last season, Leverkusen was actually considered an under dog, it was the result from last season that geve them some sort of elevation in the Bundesliga such that so many persons began to give them that preference usually accorded a big team and so if they haven't been able to meet up with the level of performance they had last season for this season and they are still around the top four, they are actually not having a bad season, for me they are doing just fine as the kind of team they would be regarded as before ever they won the league title last season, if not for that they were the champions last season, we would consider their current form and performance as a really good one as compared to that which the had 3 season ago.