I think your right they do not use much evidence based data and probably tend towards a conservation lower number.
I think they could do a lot better, if these hunter surveys are only looking for trends, what is the point in that.
You could look at a trend, oh we had 100 deer killed in car accidents last year in WMU 60 what would you do with that trend?
Issue more tags because you think the trend indicates the population is to high.
or
Issue less tags because you lost 100 animals.
I know that sound simplistic but as it stands the questions asked are not really of any practical use IMO from a management point.
The MNR on their beat's could drop into local butchers and get a count on the animals that have been processed. The tags are with the animals so you have a definite numbers, there is no compulsion for this information to be given but most processors would have no problem.
The question for sightings should be changed to ascertain how many individually identifiable animals you saw.
The count you get on the trail cameras should be included, pretty easy to tell animals apart.
SO this year I saw with my own eyes 5 individual animals I could identify.
On my trail camera I had another 3 individually identifiable animals for an accurate total of 8.
The problem I see with the present question if answered honestly is that you get a very low count from hunters as deer are so good at hiding.
We all know mature bucks are experts at avoiding hunters during the day, but get captured on cameras all the time at night.