They extradited him by force because Venezuela wouldn't. They don't have an extradition treaty. If Venezuela doesn't want this to happen again - negotiate a treaty.
The USA doesn't "accept" the ICC because it's not a party to the agreement. There are not-insignificant constitutional problems with the USA being a party. It's because they have such strong civil protections that those issues come up.
The ICC is also complementary - you misunderstand what it is for. If the USA is able to prosecute this guy themselves, you don't need an ICC, because it doesn't apply in this case.