I mentioned the cost, weight, size, etc. of DSLR cameras and that you would really have to have far more passion for cameras than biking because there comes a point where you start worrying far more about the expensive gear you are carryign than the bike ride.
Similar with very expensive nice touring bikes compared to a cheap, functional Trek 520 or Cannondale T800. Are you going to just use a simple cable lock to lock up your $5,000+ touring bike outside a museum in Munich and go in for a few hours? I did that with my Trek 520 and was not too concerned. Not sure I would do that with a bike costing 4 times as much. And $1,000 of Arkel panniers on top of that.
How many Cadillac Escapade SUV trucks are driven off road where they will get dirty, scratched, etc.? None. How likely is it someone with a $5,000 bike and $1,000 panniers will ride down a gravel road and lay their bike on the ground to see some nice sight? Or will they just ride on by because they don't want to damage their gear?
I think bike touring should be about seeing the landscape, meeting the people, etc. And take pictures to help remember. The gear you are using should never interfere with these priorities. Riding at home I have bad weather bikes and good weather bikes. Both do the job but I don't take the nice bike on bad weather days. Same with a camera. If on a bike ride where a camera could easily get lost, stolen, broken, I would take the camera I don't worry about if anything happens to it. Save the nice camera for rides or trips where there is less worry about it.