The penalty for ignoring the mandate: Impose an annual penalty of $95, or up to 1% of income, whichever is greater, on individuals who do not secure insurance; this will rise to $695, or 2.5% of income, by 2016. This is an individual limit; families have a limit of $2,085.

The average annual cost of health insurance: Average Annual Premiums for Family Health Benefits Top $15,000 in 2011

$2,085 vs. $15,000... and I can obtain the insurance when I need it? Hard choice.  Let's take the mandate and scam the system.  We'll screw the responsible people and the insurance companies.
That's the real argument for the individual mandate.