As of that date Sevilla deserved to eliminate every single one of their opponents remaining in the tournament. In the finale they deserved it again because of showing a great performance at using penalties. They become something different when it comes to the Europa League even if they perform badly in the La Liga.
This can be compared to Real Madrid, who are similarly very excellent in the Champions League and frequently outperform their domestic league. Sevilla's story is completely different; they are the only team with the most Europa League titles and have never lost in any of the finals of the Europa League. Isn't it wonderful to applaud the club for their consistency and proving to be a fantastic team in the Europa League? AS Roma played a superb game in the finals, but Sevilla were luckier to win the trophy again, this time by a wide margin ahead of other clubs that have taken it before.