Right, if someone breaks into your home you have to WAIT until he/she does a level of violence before you do that level of violence. That's clearly moronic.
Different country different values. I don't think too many Canadians are overly upset by this but could be wrong. Canada tends to be quite a bit more communitarian and socialistic compared to the US although this might be a bridge too far, but I am not sure castle doctrines would sell well here either.
I don't know enough about Canada but in the Netherlands a jeweller once killed a robber and according to a poll 62% thought the jeweller should not be prosecuted (only 19% who thought he should be prosecuted). 77% considered death an occupational hazard for burglars and 48% thought citizens should never be prosecuted for crimes committed on burglars in their houses (and 43% disagreed).
Anyway, I think defending yourself in your own home should be legal (self defense doesn't cover locking burglars up in torture chambers or shooting people who obviously aren't a threat anymore though). People shouldn't underestimate the emotional impact burglary can have on someone. I know someone who literally couldn't sleep in her own home after a burglary and eventually moved. Burglars can go f**k themselves.