By meaning, "gibberish" is a collection of letters, words, combinations of letter-sounds, or excessive punctuations used in writing, that make no sense within a particular language. They may be few, such as "xtb", or extensive (many used at once).
Based on this meaning, "gibberish" could be created using any language. For example, if I was a Spanish-speaking person, I could create a "gibberish" phrase or sentence using letters, words, and excessive punctuations. As an English-speaking person, I could write a nonsense sentence such as: "Battery bake star hop up universe. Whether in English, Russian, Polish, German, Spanish, French, etc., gibberish is nonsense-- e.g. - it makes no sense.
As for punctuation, there are rules in language for where to use a comma, exclamation point, question mark, period, etc. As a way to add expression, intensity, or as emphasis, some people use 5 or 10 question marks when just one is all that is required. Some people use multiple exclamation points, either one after another or with each separated by a single space, to indicate emphasis or to be emphatic! But, readers are distracted by 9 or 22 exclamation points after a statement or sentence. Also, and more importantly, a statement (sentence) has the same meaning whether a writer uses the standard "one" exclamation point -- or if the writer uses 6, 7, 8, or 9. "What a bad doggy!" only has ONE meaning: The dog did something bad. Adding more exclamation points doesn't make the dog be any more misbehaving than what "bad" implies.
So, in essence, gibberish is a NON-language because it impedes and hinders communication and understanding between the writer and the reader. For this reason, teachers, professors, schools, colleges, employers, and reputable websites want writers to use all the rules that govern the written word. On WikiAnswers and on Answers dot com, we ask that in the Answers section for writers to use standard words, complete words, no texting language (ex: U for you), and to use proper punctuation. Some answers require a language other than English, like, How do you say bus stop in Spanish... but the answer must still follow the proper written form used in the Spanish language.
Note: The only place on Wiki Answers and Answers dot com that punctuation is not required is in the Question box. In fact, the software often rejects questions that include punctuation.