This is simply because people do not want to take the time to learn proper grammar and spelling, or use it, when asking a question. Others haven't learned the proper grammar or spelling yet.
An edit is when, you modify the answer to a particular question by posting new content or modifying sentences etc. Making changes to spelling or correcting grammatical errors would come under minor edits.
Questions should be interpreted at face value; if there are obvious spelling errors (such as using "dose" in place of "does") then fixing those errors may make the question more answerable. If you are unsure of what a question is asking, it's best not to answer it.
No. They are edited sometimes, but not to make them more of a riddle than a real question. Our goal is to provide information, not make questions unanswerable. When a question is edited, it is usually to make it much more understandable so that people can answer it. Questions with spelling mistakes, grammatical errors etc are corrected so that it would be identified and answered by the members of the community.
As much as I enjoy answering questions, I must agonizingly read through many grammatical and simple spelling errors. Removing the old wallpaper proved to be an agonizingly slow and tedious process.
Spelling & Grammar
People like to ask questions. What may seem silly to one person may not be to the next person. And sadly, some people do have terrible grammar and spelling skills. This can be for any number of reasons including English not being their first language.
All math questions should not be full of grammatical error and they should not be impossible to answer. Worded math questions should be grammatically correct and be able to be solved in a few steps.
This is so more people understand the question. Quite often, questions are asked with grammar/spelling/capitalization errors which must be fixed. In addition, questions can be reworded into a better form to fit the Style Rules (see 'related questions'), in order to be merged into a similar question.
Grammatical mistakes are errors in the usage of grammar rules in a language. These errors can include issues with spelling, punctuation, syntax, verb tense, subject-verb agreement, and word choice. Grammar mistakes can affect the clarity and precision of communication.
You can find a free grammar checker at spellcheckplus.com/. It will check your paper for common spelling mistakes and grammatical errors.
Questions seem unanswerable for various reasons -- there may be spelling problems or vague grammar. Then another contributor might come along and realize what the questioner was really asking, and offer an answer. Don't forget to correct any spelling or grammar errors in the question itself, so that others will have an easier time finding it in searches.
Questions that help Answers.com are questions about popular topics that users might come looking for answers to. They should be informative and well thought out without spelling or grammar errors.