Guilty confession ... I actually kinda dig those groovy old MTB bike bars with the integrated quill stem - purely for the aesthetics - no other advantage to them that I can think of.
Those bar/stem single units are common here on Venture Mountain Tour bikes - which were obviously sold by the boatload judging by the number one sees still, rarely in lovingly kept condition, often still functional (or nearly so) - big box house brands, eh? Might be off the same assembly line as the OP's bike.