That's why they charge in at O'dark thirty.
It's known that the occupants are sleeping, and a sleeping (or half-awake) person offers little to no resistance.
In my case I would be likely up and getting ready to go to work at what other consider "O-dark-30".
Going in at O'dark thirty without proper declaration is a good way to get shot by your standard home owner. I live by a very good assumption that someone breaking in my front door at 3am is up to no good and intends me harm. Further, a person in that situation has only been provided seconds to make a life or death decision after being torn out of REM sleep. Making it doubtful that they cognitively understood the screaming that woke them up.
Kick in my front door and start screaming at 2am and my first reaction is to grab my gun. Three seconds later, I'm on my stair landing and I see two people in black running up my staircase towards my children's rooms. I now have 1 second or less to decide to shoot or put my family at their mercy.
Doesn't sound too safe to me.