Guess that depends on where back home is. I was recently in NYC, and several other cities in the surrounding area- bars on all the windows in most areas. Then I was in Spain, France, and Italy- the same- bars on all the lower levels. Where I come from in Canada many people only lock their doors at night and only the liquor store has bars on the windows.
As I've never really been to the US (except 3 nights in Miami while traveling to the DR), I can only say what others have said, and based on that, many NA cities might be actually more dangerous than some places in the DR, and the three other places (apart from Canada) you list are southern European (and middlish European) countries.
I do know that in Germany some houses also carry metallic shutters in the first floors, but not all.
Where I come from (Northern Europe), my dad owns a big house 3 miles from the city center, he doesn't even have a proper lock (yes, it's a lock, but very simple and 50 years old) in the main door. All expensive garden machinery (lawn mower, car parts, tires etc. etc.) he has in a garage that doesn't even have a door (not built, not because it would be broken...). Has he been stolen something - never - and his family has had the house for 70 years. The city has a population of close to 200,000, so not the smallest village...
The first ever apartment we rented together with my wife (then-novia) was in a relatively good barrio, second floor. The construction was new, no bars in windows. I could not understand that she wanted to close the windows for night, said that we'll get robbed if they stay open. I didn' belive her back then... Having a pretty strong will, the windows stayed shut - always...