Alonso is a figure who has made history with Leverkusen. Leverkusen certainly will not forget what Alonso has given them.
Alonso is a good coach and the right coach to handle Leverkusen. Indeed, this season at the beginning experienced obstacles that made them have to accept the fact that the points difference with Bayern was 6 points. So this is not a benchmark to judge Alonso as a bad coach even though no one here said that to Alonso.
Even though they are certain to fail to defend the Bundesliga title, I think Alonso is still worthy enough to be Leverkusen's coach next season and what the club needs to improve is how they can bring in some quality players so they can compete again for the Bundesliga title next season. Leverkusen had problems at the start of the season so they had difficulty catching up on Bayern Munich's points and that was not entirely Alonso's fault.
This is the challenge that needs to be done and the management must try to make big changes if they want to make Leverkusen one of the strong teams in the Bundesliga and that can be achieved if they have good financial resources in getting new player signatures.