As an option, that's fair - but I think if you make the bed any shorter than 5', that would pass the tipping point between having the option to grab sheet goods from Home Depot or not. Depends on the use case for the overall market, I suppose.Needs to be a king cab. You can't leave anything is the bed of a PU anymore.
Adding a bed cover to my truck has made me more comfortable about leaving things in the bed while I run into the store - so long as losing those items wouldn't be a catastrophe. If the day comes that someone pops the cover open with a pry bar to get my propane tank, I'll have to come to terms with that.