Kizaru was causing wanton destruction at Sabaody for no reason at all, and Aokiji was so careless with his abilities at MF that he overdid his freezing and prevented the walls from being able to be lifted up in time. The only one who arguably cared enough about preserving MF was Akainu, and even then I doubt he cared enough to do anything more than just slightly nerf himself.
It’s not fair to compare that moment against WB against BM having the chance to finish off Marco. WB was in a vulnerable position because of his heart attack, which had nothing to do with Akainu, while Marco was in a vulnerable position because BM herself grabbed him