Of course they don't: they're career criminals led by one of the most infamous betrayers in the entire Marvel U: Doc Ock. It would be more strange if they did get along.
Me, I prefer the non-Kraven Six, which I guess you could also call Larsen-era:
Ock, Electro, Mysterio, Demogoblin, Vulture, Sandman. Its classic without having to look at Kraven... anytime you can avoid that, I say its a plus.
Sorry Kraven fans, in my opinion his powers are not sufficient to land him a place in a supergroup like that. Venom has no place in the Six either - talk about not getting along with people, he leads the list.
*Ock: mastermind. Check.
*Electro: proverbial big-gun who's quite easily manipulated: Check
*Vulture: providing air-support for the mission. Check.
*Demogoblin: more air-support, plus a soupcon of nutty religious stuff. Check.
*Sandman: has the ability to discorporate and slip past almost any barrier. Useful. Check.
*Mysterio: master of illusion, provides handy hallucinatory images to cover everyone else's escape. Check.
*Kraven: Can communicate with animals.... in Manhattan? In the jungle this would be useful, or if planning a mission at the zoo... but how useful is that during a bank-heist? UN-check. Someone give Smerdyakov a call - now *him* we could use.