I can remember shortly after 9/11 where one airline apologised for removing metal cutlery. And then brought me my wine in an individual bottle. Which is more dangerous, a crappy butter knife or a broken bottle
As for dress code, wearing clothes to cover your skin may be worse as some materials would melt onto you. I have full flame proof clothing (underwear upwards), but i am not going to wear that every time I fly. Nor am I going to wear clothing that will make me uncomfortably hot on an aircraft.
Oh and a jumper could get wet and drag you down if you land in water.
Common theme - people often address minor risks by worsening a more major risk