Why are people prevented from editing thier questions of typos and spelling errors, that appear after submission, rather than before.?

I have NOT HAD THAT PROBLEM.  Though I catch the typos right after posting it and then rereading the question so it is basically immediately done before I get an answer.

Imagine changing the question after an answer has already been posted. The potential for great confusion and the end of the world as we know it is great.

Because that would make it possible for someone to change their question completely, thus falsifying the answers given. If I ask, "What do pesticides do to pests?" and several people answer, "Kill them," then what's to stop me from changing my question to, "What should Whites do to Blacks?" or, "What would you like to do to the President and his family?" That would make all the answers so offensive those accounts could get suspended, or even result in the answerers being criminally investigated by the Secret Service. Nonsense like that that would definitely happen is why you can't change your question or edit it in any way. All answers depend on it, so changing the questions perverts posted answers. If you need to make a change before an answer is posted, you can delete the question.