While it is a good idea to keep questionnaires sent to a wider audience to a minimum to ensure greater number of responses.
I am sure that the community would be very willing to answer a lot more questions at a time.
If many more questions need answering, if links to such were posted on the forum I am sure there would still be good responses to questionnaires that take more time.
I don't quite understand what you are hoping for here. The forum allows anybody to start a threat and share their thoughts.. we all know that the devs are active here and will get your feedback without prompting for it through a survey or questionnaire.
The forum encourages others as well, sometimes giving insight into things they otherwise wouldn't get from a form fill and submit to the survey.
If there is some burning question you have in mind that you really like to give your input to bitshares on.. why not here?