It is the largest single expense to employers and to the [Canadian] healthcare system. It is not dystopian to want to track smokers on their journey away from smoking - it's the only way we know if we're getting better at helping them quit.
28 days is a good measure of smoke free. By that time, you are through the nicotine withdrawal of about 72 hours, which I think is the biggest cause of relapse. After that, you need to resist the social and habitual pressures, and that is wholly up to the individual. Some people can go 20 years resisting these pressures, others collapse in a few days. So 3 weeks is a fair balance, I think.
[1] http://www.cbc.ca/news/business/smoking-economic-cost-1.4357...