Eating and drinking did not come about because of Islam, The prophet was not the first one to eat and drink, and all kinds of people eat and drank including polythiests, christians and jews. So I guess thats ENOUGH! Other people may well have been wearing headgear but maybe Islams differed from theirs. If you gonna say all those things which other faiths did at that time/do, like Islam, then you will come unstuck. Islam has taught us how do do things in the correct way. the way in which Allah will become most happy with us.
Asslamo Allaikum, Lets go with your logic for a minute here... If headgear was wore by previous nations and previous prophets and Rasul-ullah (Sallaho Alaihe Wassallam) continued the practise then that you would add more weight to the argument and not lessen it, i.e. if ALL PROPHETS followed a practise and We (Muslims) believe that all prophets were DIVINELY GUIDED , then why would we want to IGNORE the practise of previous nations and previous prophets (including Rasul-ullah (Sallaho Alaihe Wassallam))? Surely prophets have more knowledge & wisdon then us?