That's why I said the original
series.
His first and only victim until he escaped as an adult was his older sister.
He killed her and then when into the catatonic state that we saw him in when his parents get home.
Then when he escapes,Loomis knows that he's headed home.
And then his sister's grave stone goes missing.
So while it might not of been planned from the beginning or explicitly stated,it wasn't hard to make it seem like Michael was primarily focused on family.
And it was only part 2 before they did.
The only person that Michael killed in the first movie that wasn't connected to Laurie in some way was the guy he got the boiler suit from.