you seem to think that the only way to protect yourself from burglars is to have a gun. I think that trying to confront the burglars yourself is a very risky strategy as they could be more ruthless than you and shoot you first. Surely deterrence is better that confrontation.
You seem to think that everyone can afford the "deterrence" you suggest. Then there are other factors. People prefer living in homes, not fortresses. And in the current economy, most people live in apartments they can't legally alter (without a landlord's permission) even if they wanted and could afford fortress-level deterrence. Confronting a criminal or nut is a risky thing to do. But homeowners can be some pretty tough customers, too, if their homes and lives are threatened ... especially homeowners who are trained and well-practiced with the weapons they use to defend themselves.
How much is a human life worth?
How much is the trauma of having shot someone worth?
Buying a gun and obtaining suitable training costs money, too!
All you need is a sturdy door and a good quality lock. Over here sturdy doors come as standard and good quality locks cost from about 50 Euro (~$65). The fittings are standardised so the lock can be exchanged yourself in a few minutes. Additional pins to secure the door on the hinge side cost just a few Euro. All windows made in the past 10 years already come with security fittings built-in. Older windows can be upgraded from about 100 Euro (~$129) each. This is enough to keep criminals out for at least 15 minutes and they would have to make a lot of noise to get past these locks. Criminals know about lock types and when they see a high quality lock, it is easier and safer for them to try elsewhere instead.
I have yet to hear of a landlord objecting to upgrading doors and windows. Often they are prepared to pay at least a part of the costs themselves. As door locks here are standardised, the lock can always be changed back when you move out of the property.
Where I live, they would have to get through two separate secure doors to get into my home. High fences make it difficult to get into my back garden, too.
Upgrading your locks and windows gives you more security and peace of mind, it does not make your home, any less of a home.
I am sorry, but I just do not agree with your opinion that guns are better or even cheaper than good locks.
If I was to hear someone trying to break in, I would call the police and then announce loudly through the door that the police are on their way and perhaps it would be wise for them to get lost.
In some of your comments, I find your lack of regard for human life and willingness to put yourself at risk, reckless to say the least.
To Peter my mothers mom had a saying "A Locked door only keeps an honest man honest, if someone is going to steal from you they will find a way in"
A good locked door will also keep a dishonest man on the other side of it. At least for a time long enough for the police to arrive.
Other simple deterrents are lights which go on when someone approaches the house. This gives the impression someone is at home even if there is not. Alternatively, leaving one light on at home (on a timer) is also an effective deterrent.
This conversation shows the different attitude's to responding to crime. In Europe, having a gun at home is not an option due to strict gun laws (which I agree with). Investing a little money on securing the points of entry is a worthwhile investment and insurance will pay for any losses if somehow the thiefs succeed in steeling from your home. The police here provide free and neutral advice on how to best secure your home.
In the USA, it appears that for people like Alec, the best strategy is to save money on good locks and instead have an arsenal of guns so you can blow the brains out of anyone who is trying to break-in to your home. This of course will only work if someone, trained to use a gun, is home at the time of the break-in.
I know which method I prefer.