You are right — I do actually put a twilly around my Kellies’ handles, but that is partially because I have washed those twillies and I know they get filthy... seems easier than constantly cleaning the handle. I have to say that structuring my life around a bag is a bit too much for me — if I can’t use a bag to carry treats for the horse when going riding, then I am not buying one.
I do think that accidents happen no matter how protective you are of a bag. I had someone spill red wine on my Garden Party on the plane — it was on the outside, and it came off, but it was annoying. I had a French waiter trip over and drop a dish on me and my vintage ostrich Hermes once. Maybe I just have bad luck

I personally cannot imagine the level of commitment it takes to use a bag and then resell it in a pristine condition.