"Sanji got disqualified the moment he told Zoro to give up his dream."
People got trash comprehension nowadays.
Shanks sacrifice his own arm to Luffy and Luffy is indebted to him. Same thing for Zeff sacrificed his own leg.
And Sanji is grateful for what Zeff did for him.
Sanji doesn't know if Zoro have a person that he owe his life to or not.
Zoro talks about giving up his life after becoming a invincible swordsman. And Zoro saying the word "Crazy"
That's why Sanji was telling Zoro to give up his dream because Zoro was calling himself crazy and would rather die against the world's best swordsman. Sanji doesn't know if Zoro has other person that he have to repay for.
And then after seeing Luffy's and Zoro's determination, Sanji redeemed himself and understand their motives.
Just like how Sanji cannot live in a world without Zeff because he can't repay for what Zeff did to him.