It would be inappropriate for anyone to blame a coach like Xabi Alonso who has looked after and brought the Leverkusen team to an even more extraordinary level this season. Because Leverkusen has also succeeded in winning two trophies this season even though they lost at the wrong time in the final match of the Europa League this season. And I think people who are willing to blame Xabi Alonso just because Leverkusen lost the final match are people who don't understand the pressure that Xabi Alonso is under and maybe also don't understand how football works for all teams including Leverkusen.
It doesn't make sense if there are people who blame Xabi Alonso. People can feel unsatisfied with Xabi Alonso because Leverkusen failed to win Europa league trophy. But it is true that Leverkusen could win 2 trophies in German domestic competition (Bundesliga trophy and DFB Pokal trophy). Leverkusen even made a record in domestic competition this season, they are unbeaten in the whole season.
Source: cbssportsgolazo
For the Europa League trophy, Leverkusen may be unlucky because they choose the wrong strategy. It will be a good lesson for Xabi Alonso and Leverkusen players, they must always remember to choose the right players on the starting lineup. In the final Europa league this season, Xabi Alonso used inappropriate starting lineup. So, the game of Leverkusen can't be effective, they got a difficulty to score goals.