The law in the UK, covered a billion times in other threads, allows you to use reasonable force in the circumstances. So if you're attacked with a paperclip, you fight back with a paperclip. If you are attacked by a knife, you defend yourself with a knife. If you're attacked by a gun, you unlock yours and fight back with with a gun. Does that sound logical?
In America, someone fights you with a paperclip, and everyone whoops and slaps hands because you went straight for your gun and shot off 40 rounds.
Do you not see the idiocy in that? The experienced fighting bad guy breaks into the home of the senior citizen couple. Bad guy has a knife. 70 year old man must now have a knife fight with a bigger, younger, stronger, more experienced bad guy and if he loses, well, tough shit?
Here's how I fight: I fight to immediately overpower my opponent with every thing I have available to me in the shortest time possible. If I fear death or great bodily harm to me or mine, I use overwhelming force, not like force. The fight will be over in 20 seconds... Either me or the bad guy is going down and going down either in disabling level of pain or dead...
By your rules, the weak are always just victims. If you don't want me to use all available force to defend my family or me, stay the **** out of my house.
Edit: and I forgot to mention. If a bad guy breaks into your house you'll have to have an array of weapons available so that you can match the invader. You wouldn't want to only have a baseball bat when the attacker has only his fists.
Keep a full array of weapons and then ask the invader to please let you know what weapons he has and hold off just one second while I select the appropriate counter weapon.
In my house, we will not be having a fair fight. If you break into my house I will overcome you with all available force and I will do it in seconds. It only takes less than 2 seconds for a bad guy to kick in the door, cross the room with whatever unknown weapon he might have, and end my life or my wife's.
I have an amazing home security and surveillance system and I'll know, 24/7, that you're coming before you get to the door. I'll be prepared when the door opens. What I won't know is what weapons or firearms or knives or other things you might have to harm me. Given the time I have to decide, I will assume a gun or knife and the intent to use them. A home invader probably has about a quarter of a second to recognize their mistake and either collapse submissively to the floor or change directions back out of the house. It would never be my intent to hurt or kill them but I will absolutely stop them or die trying.