Why do teams that qualify for Europa League have cr@ppy GD?

i actually think 4th place in serie a should get CL not top 3, but i dunno, plus i dont think tottenham wants europa, redknapp said, he rather be 6th so then he can focus on getting CL football next season and yeah i think its wrong people disrespect europa league especially the english media, i think its underrated, certainly not better than champions league but europa league is quite good, like villarreal vs fc porto, what a fantastic match that was, plus both of them has plenty of experience in the CL