Indeed Manchester United were a failure to me. Of course they faced the king of the Europa League on paper. However Sevilla were having their vulnerable times back then so Manchester United should have finished them off in Old Trafford. But Sevilla were really lucky in the last moments of that game and got a draw somehow.
And as of the second leg Sevilla started a really solid run which brought even the title to them at the end. Did Sevilla deserve the title at the end? My answer would be yes to that. Even though having big difficulties in general of the season they still found a way out in the Europa League after facing Manchester United. This time period is a product of hard work.
Can't blame Manchester United for losing the game against Sevilla.
They had a good performance and they could easily win the game but the reason for Manchester United losing that game was mostly that they had many personal mistakes against Sevilla and especially the defenders were totally disappointing otherwise we could see Manchester United playing in the final match instead of Sevilla.
Manchester united tried in the competition in Europa League and their game with Sevilla was not bad, I don't see their performance to be very bad that made Sevilla was able to eliminate them from the Europa League, Sevilla is just this lucky team when it comes to Europa league. Manchester United perform well but their loss to Sevilla was as a a results two physical challenge of the players which made them not to be able to obtain Victory both in the first leg and second leg match with Sevilla .
Manchester United over used their players that it got to the point that they were all ready exhausted, I think this was why it was so easy for Sevilla to get advantage of Manchester United by eliminating them from the Europa League. If Manchester United have had many players to substitute some of their player it would not have been easy for Sevilla to win Europa League. I see no reason to blame Manchester United players failing to win Europa League.