I really disagree with you there, NOAD. Look at it through the eyes of the homeowner...
You're woken in your bed in the middle of the night and you know that someone is in your house. First reaction is more than likely to panic; you don't know what they're after. We've heard so many times of burglars not being happy with just robbing the gaffe, they want to pour boiling water over the people in the house/rape the wife or daughters or worse. Some burglars are proper nasty pieces of work and aren't merely chancers after your treasure.
If it were me, I imagine I would lash out with as much force as I could muster. Like an earlier poster said, you get one chance to inflict harm to the burglar. Make a bad job of it and they're likely to harm you more. So you make sure they're unconcious, if you can. If it's a choice between me and my family getting harmed, burglar is going down every time, I'm afraid. Being a burglar is a risky business. Getting harmed by an aggrieved homeowner is an occupational hazard.
FWIW, I have sufficient insurance but burglars do untold harm beyond the hassle of needing to ring round insurance companies trying to get your goods back (which YOU will end up forking out excess for anyway most of the time) Thankfully, I've never been burgled but I remeber my aunt and uncle being burgled and going to their house the following day. The house just didn't feel 'right'. My cousin had to go for counselling because she had disturbed the burglars and it shit her right up (as it would do at 7 years old) They're just awful, awful people.