He Was Their Dick (and they loved him)
It's really hitting me again how the Kraken crew saving Izzy was such an act of LOVE.
There was nothing for them to gain by saving Izzy once he'd been shot by the Kraken, nothing at all!!
Not even the possibility of Izzy protecting them from Krakbeard, since the deranged captain had already made it very clear he wanted Izzy dead.
Also, as Izzy was very badly injured at the time, it could be assumed that he would not be able to move from his hiding spot.
Since Krakbeard basically signed his death warrant, Izzy would never be able to move freely aboard the ship without facing rhe Kraken's wrath. He would have to stay sequestered in that little hidden room.
If anything, the crew keeping him alive was making their own lives harder, as well as putting said lives in danger.
It would've been much simpler and straightforward to shoot him, throw him aboard, and shrug it off as the humane way to end his life. We'd seen them waste others with little remorse, after all, and Izzy had been a dick to them in the past anyway.
Almost immediately after Izzy had been shot, one or perhaps all of them must have decided to take that chance to save this seriously wounded older man.
They had to quickly find a hiding place, haul his body, do their best to treat his wound, keep him sedated and quiet as best they could, then sneak him medicine and probably food and rum, help him relieve himself and clean that up.
They would have to do this for the foreseeable future, as Krakbeard told Frenchie in no uncertain terms that he had no intention of ever going back to land.
They would have to keep him alive and hidden for as long as the rest of their lives would allow on that doomed ship.
Surely that would sound like too much trouble for a crew that was focused only on living second to second? Not even Archie really understood their reasoning at the time.
All the same, the ever-opportunistic Frenchie and survivalist Jim put aside their self-preservation instincts just to hide this guy and keep him safe.
Fang had known Izzy for the longest, so it stood to reason that he would be the most inclined to help. And yet, Archie and Jim scrubbed Izzy's blood from the deck while Fang cried and Frenchie was likely tending to Izzy.
Frenchie also went to fetch medicine for him, and Jim and Archie cut off the rotten leg. While it's likely that Fang was just too traumatized to see Izzy in that state without crying and drawing attention, the fact is that the other members of Kraken crew stepped up when they really didn't have to.
Frenchie jeopardized his own position as first mate to lie multiple times to cover for Izzy.
Deranged as the captain was, first mate is considered a pretty privileged station. One would think a clever guy like Frenchie would try to get in the captain's good graces to try to ensure his own survival and not do anything that would potentially get him in big trouble.
And yet......well, you get the picture.
The Kraken crew risked it all for Izzy, and they did it for LOVE