The same reason they didn't just kill Ace right away, rather than waiting for Whitebeard to show up.
The same reason Kizaru shot the key in Luffy's hand, rather than Luffy's head or heart
The same reason Kizaru and Aokiji just let Law and co. go after one attack each
The same reason Kizaru didn't stomp Zoro right away
The same reason Kizaru didn't just use Yasaka no Magatama on the Strawhats
The same reason Rayleigh sliced Kizaru's Yata no Kagami path, rather than slicing Kizaru's head or his body
The same reason Kizaru intercepted Luffy by kicking him into a building, rather than Akainu intercepting him by driving a magma fist through is chest/throat/head, or Kuzan by freezing him, then smashing him to pieces
I don't seem to understand why are u bringing up ace's execution.
They scheduled Ace's execution for a certain date. There are certain rules. Like the time it took to gather all the marines
Sengoku most likely wanted everyone of his subordinates there when he told them who Ace his father was. They can't just kill him. arrangements have to be made. It's the same as in our world.
Someone on death row has to wait before he gets killed to
Kizaru shooting the key or not killing Zoro has nothing to do with plot. it is a character trait of him to be lazy and uninterested and just in general be a troll is his persona. Not everyone is Akainu.
Aokiji and Kizaru maybe thought there was no way Law's submarine could have survived that?
Kizaru already witnessed first hand how fodder all supernova were so imo he just thought . Ok they are done
Is it that hard to believe Doflamingo is just stronger than Law? Does it nag u that friggin much so u have to blame plot restriction for it?