The issue of wearing must be left to the riders; making it compulsory will oly produce more law breakers. Though the argument in favour is higher chance of survival when there is a head injury, those against are constricted feeling, sweating, reduced awareness (vision, sound) of surroundings, and comfort. The married set wears it without fail especially when wife and child are co-passengers, the young set wear it mainly to escape police fine/ bribe. Helmets make the yuppie set more dashing and risk taking because of anonymity.
So what is required is more education, society and family pressure to adopt safe practices and leave it to the individual to decide for or against. A couple of years ago, the son of a doctor couple in chennai took his father's bike to buy a takeaway from a food joint nearby, and died in an accident close to his home. The boy was 15, well below the legal age for driving, and his parents had allowed him to ride the bike.
I am of the opinion that when only the individual is affected and has to face the consequences (non wearing of helmet, seat belt, suicide), it is better to leave the decision to the individual, but apply a strong family and social pressure to conform than passing stringent laws. Of course stringent laws are necessary when the individual's act results in damage to others like drink-driving.
There was a similar argument when seat belts were made compulsory - the driver is sure to die if there is fire caused by an accident or otherwise. Last month, in pune, maharashtra, a self employed businessman, finished his one hour morning jog/run and breakfast, and then started his car (volkswagen polo). The car caught fire soon after start and came to a halt after damaging a few vehicles. He could not open the door or get out; people on the road rescued him after breaking open the windows (self locking safety feature is active). He suffered sever burns and died after a week in hospital.
So, when only the individual is affected (helmet, seat belt, alchohol, drug, smoking etc.), it is better to leave the decision to him/her, but apply strong family, society pressure to do the right thing.