Lets try a few facts.
- the performances of the Patriot missile during the war were poor - Correct. The patriot missiles were designed as AA missiles, and were converted to location defense against ballistic missiles. Had they been used for their purpose - protecting an isolated base from a missile attack, they may have done somewhat better. Protecting densely populated areas with them was a mistake.
- more than 70% of all civilian masks were malfunctioned, and would have been futile in case of a chemical attack - Partially correct. While many of the gas masks were outdated they offered better protection than no gas masks at all. The efficiency of active-carbon filters is reduced with time, as they get exposed to humidity. Gas masks that aren't fully sealed with filters that aren't in the best shape aren't what you would want to give your child (actually, you'd probably rather your child wouldn't be in a situation that makes this question relevant), but it beats the shit out of being protectionless.
- Protection wasn't efficient against VX, that requires a full protective suit - Incorrect. While a person working or (more likely) fighting in an environment contaminated with VX should certainly wear a protective suit, VX is heavier than the air and is mostly in puddles a short time after an attack (initially it's in aerosol form, but it generally accumulates on the ground after a while). In the case of a VX attack, the walls and windows of houses that didn't collapse/break would provide most of the initial protection necessary. Population would than be evacuated from the region through paths that would have been partially decontaminated, and the simple act of wearing boots and not touching anything with your hands would have gotten most of the population out alive. The atropine given as first aid to the population works against all acetylcholinergic nerve agents, including VX.
The protection given to civilians at the time by "Haga" - the civil defense authority (The home front command didn't exist at the time) was far from perfect, but would have seriously reduced casualties in the case of a chemical attack.