Adding bug reports to askubuntu would cause several things:
It will make it difficult to find answers to problems that end users have. Looking for a solution will involve going through bug reports that do not yet have an answer and the answer will not be available until the bug is fix.
The answer to at least most of the bug reports will be: When the fix is available. Basically throwing out the idea of the answers.
It will create a problem with launchpad and the bug report system (which I honestly find very well made) by adding around 1000 bugs per month to askubuntu if not more which would create even more work for Moderators not to mention looking if a bug report that was made had a correct answer, was a duplicate of a similar bug and any other situations that actually show in launchpad for the bug reports. There are situations that are for bug reporting only and others that are for questions that need specific answers.
I am assuming there will be less freedom in doing statistics about the bug reports and ways to study the system for better implementation later on.
The idea of askubuntu is to directly go where no man has... wait sorry. The idea is to find the solution to a question or doubt you are having about Ubuntu in a easy and direct way. Saving you from time consuming reading (which in some cases is actually needed) and learning how others solve the same problem in different ways.