Lets keep this short and concise. Cost below is both economical costs and life costs and costs of loss of personal conveniences.
Lets assume that the epidemic grows exponentially and that the epidemic is one that causes significant loss in lives.
At day one in an outbreak the probability of a single individual getting infected in an epidemic is very, very low. To an individual staying at home or any kind of changes to their livelihood or lifestyle is statistically not rewarding. The problem is that at that time for the society as a whole the cost benefit ratio of early response in an outbreak is at its peak.
At that time every action the individual takes re-enforces this behavior if non compliance. When and if an individual starts seeing people around them fall, this bubble will be shattered fast and panic can set in fast.
Sadly as time passes by and the outbreak is not contained ( due to the non compliance of individuals motivated by the very low initial probability of infection ), the cost to society of curbing the epidemic increases exponentially. Making more draconian measures to curb the transmission, societies cost of adding extra layers of protection increases linearly ( as an assumption ) as a multiplier over and above the existing exponential increase of the epidemic.
If the epidemic is contained all individuals that did not comply and have not seen within their circles the effect of the epidemic, will as a result in further reinforcing their bad agent behavior.
Assuming this happens a few times in the life time of such and individual, the more such individuals are exposed to what could be excellent government early policies will only add to a “psychological immunity against conforming to epidemic regulations”. Sadly the more effective these measures are the more resistant such individuals are to follow them.
Also sadly if an outbreak is not contained either because of government slow response or population non-compliance, the higher costs of late action increase non compliance of such bad agent subset of the population.