Because of the direction of Crocodile's hook going backwards(sees the lines). Mihawk is the one who blocked him, not the way around. Not that it matters though considering like i've said interceptions feats aren't relevant. We've seen fodder okamas or daz bones intercepting Mihawk's flying slash by coming out of nowhere. Crocodile had no direct confrontations with someone relevant. He was just an annoying bastard flying everywhere but that no one cared about
And are you seriously questioning how they hurt Crocodile? Dellinger can kick thousand tones Machwise and hurt him. Machwise with his fruit upgrading his weight up to these thousand tones can destroy him if hits. Gladius can create large explosions upon contact. Senor Pink could damage post-skip cyborg Franky, same goes for Baby5 and so on and so on. On the otherside, alabasta gearless Luffy could KO Crocodile with a storm. Just accept Crocodile doesn't compete
What lines? The impact bubble that doesn't indicate direction is the only thing there.
Machvise increased his weight, this doesn't make him any more durable. 300 pounds, 600 pounds, 1200 pounds, Dellinger's hit would have hurt him all the same. He's still flesh, and therefore, still susceptible to sharp things like Dellinger's weapons.
Blow up what? What's he gonna blow up that will harm Crocodile? Not only that, but Crocodile took Impel Down's heat with no discomfort and didn't flinch in the baptizing. Transforming into sand negates the blunt force of any explosions that Gladius hits him with, and he can ignore the heat. Even if Gladius blows up Croco while he's in a sand state, Croco would just reform from the scattered sand. Haki doesn't help since Gladius can't embed the explosion with Haki, and water would be meaningless since he can't blow up flesh, which Croco would remain while wet. There's nothing Gladius can do to Croco.
Senor Pink goes into the ground to swim, Croco floats into the air, Senor Pink comes out, misses his suplex grab, Barchan dries him up. Or, Crocodile just destroys the ground while Pink is in it, exposing him, and giving him the chance to hit him with Barchan or Espada.
Dellinger launches himself at Croc, gets caught in Croc's sand body, boom, dried up and suffocated Dellinger.
Machvise tries to land on Crocodile, Crocodile skewers him with Espada, or dries him with Barchan, or simply turns into sand. Either way, Machvise isn't hurting Crocodile.
