Why the bratwurst (sausage) is so common in German?
And why every region have its own special type of sausage? 
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Why would it not be?
It’s common throughout Europe, we just call it other names elsewhere.
It was, originally, a good way to use those bits and pieces of meat and lard that hadn’t gone into “better things”. In Southern European countries we can make sausages and dry them (salchichón, saucisson, chorizo) but German climate isn’t dry enough for that; you can smoke meats, but not really dry them otherwise. So you get “fresh” sausages that need to be cooked and eaten pretty fast, and smoked ones that last longer but still not as long as the southern dried ones.
Why does evey region has its own type of sausage is due to the ingenuity of local cooks 
Well, it makes for a quick, nourishing, and tasty (if not particularly healthy) snack. Basically, bratwurst is the German equivalent of the American hot dog; you can get it from a street vendor or small fast food outlets and eat it while standing or walking. They are also a favourite during barbecues (being somewhat cheaper than steaks or cutlets, which are also grilled during barbecues).
As for why we have so many regional varieties? We like it that way, I guess :). Regional variations in food are quite common in most nations, I would think. These days you can get many varieties of sausage far from the originating location.
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To put the answer slightly differently, sausage exists in most cultures because they all have the same problem: what to do with left over meat from an animal?
Sausage provides an easy solution. You put the meat all chopped up in bits into the casing of the intestine, then you do something to the encased meat to preserve it, such as salting it, drying it or smoking it. You now have a handy way to eat said leftover bits of meat that aren’t easily dealt with in their natural form (as, say, a steak is easily dealt with).
You could say that sausage exists in so many variations for the same reason cheese does. Cheese, of course, is salted milk, that is, milk that has been preserved through a salting process (and, of course the transformation of certain bacteria). Milk is way too important to be allowed to spoil without preservation; so, too, are the otherwise unusable portions of the animal.
This is NOT intended as a comprehensive answer, and there are shortcuts in phraseology. Don’t get all nitpicky. 
Why not? American hot dogs are.
Don’t be silly. Hot dogs are made of show-off athletes.
Mr. C K Dexter Haven!
Thank you for your warm welcoming.
I appologize for the misunderstood. I thought that their is no links between the diffrenets forums, and also couldn’t see the question on the list in the begining.
Thank you for the explanation- I will read the rules in the begining next time.
And very glad to discover this fantastic website- it is help me alot.
Anat 
Google Ads are for Sausage Stuffers.
Make of that what you will.
Yah, but only the wurst brats.
Mmmmm…bratwurst and red cabbage. I know what I’m making for dinner tonight!
I’ll take two, please.
Interestingly, I just had dinner the other night with a man from Italy who has lived here for several years, and he was very put out that “Italian sausage” in the US has fennel (he called it finocchio, rhymes with Pinocchio) in it. He says this is not common in Italy, but a very specific regional sausage that’s considered something of an acquired taste. He said the best thing for “real” Italian cooking in the US is polish sausage!
Can anyone confirm or deny? The Italian descended Americans at the table were all nodding as if this was common knowledge, and he’s a fantastic cook, so I’m inclined to believe him, but it’s the first I’ve heard of it.
Poll: What’s your favorite German sausage – bratwurst, knockwurst, or something else? (I’m partial to knockwurst – it goes well with sauerkraut.)
That sounds like some kind of epithet. “You-- you sausage stuffer!”
Fleischwurst. Essentially steak tartare for sandwichs, with slight herb and garlic. Mmmm, nummy.
/relurk
Braunschweiger! My husband and kid #1 think it’s the most disgusting thing ever. Kid #2 loves it on garlic toast. (So did kid #1, he just doesn’t remember it.)
Anat, perhaps it is easier to think of and compare your local culinary delicacies. I do not know your ethnicity or cultural origins, but perhaps there is a local dish that is unique to where you live. It is always duplicated or done slightly different from area to area. Such is the variation and popularity of Bratwurst.
Truly, in the German language any wurst (sausage) can be gebraten (roasted or grilled). The sausage that has become known as “the grilled sausage”; a white, part veal, part pork, understated sausage is the standard as popularized in Southern Germany. But a “bratwurst” is truly local and always slightly different wherever you are in Germany. Some butcher or Restauranteer will make it their own and influence the region’s savor. Many Generations and the taste of the people make such.
Maybe you have a certain preperation or recipe for a favorite meat in your region, often duplicated, but never quite the same as home?
My vote goes to the Thueringer Rostbratwurst.