You seem to misattribute perfect knowledge, control, aim, and rationality to a scared person with a gun.

edit: some examples of scared shooters acting out of fear without enough information shoot people who are not "intruders":

  - Connecticut teacher mistakenly kills son after neighbor reports robber [1]
  - Ohio Father Fatally Shoots Son He Mistook for Intruder: Police [2] 

[1] https://www.cnn.com/2012/09/28/justice/connecticut-father-ki...

[2] https://www.nbcnews.com/news/us-news/ohio-father-fatally-sho...

So people shouldn't be allowed to defend themselves because sometimes there are accidents? Should people be allowed to drive? After all, some people drive drunk. Should people even be allowed to go outside at all? After all, people get hit by meteors and lightning bolts.

> After all, some people drive drunk

In my example, your drunk driver would be the shooter, not my the shooting victim.

I'm very familiar with risk evaluation. This whole thread was because I was pointing out a big gap in your logic.

> In a self defense situation who gets shot is up to the attackers.

"Accidents happen" disproves this assertion.

These imperfect people trying to defend themselves are easy to avoid, you just don't break into their property so that doesn't really seem like much of an issue.