Very good points, and I must thank you for drawing to my attention a subject which I had never really considered before.
It strikes me that the Men really believed that Hobbits were a helpless race. Completely ill-equipped to deal with fighting and warfare on a large and serious scale. However wise this supposition is it is surely understandable for Kingdoms of Men - even Aragorn's - to regard Hobbits as weak and needy, and that's why they protected them so stubbornly, without regard to logic, or even total respect.
But both sides were happy enough to keep the cycle going.