Public health insurance also covers your spouse and children for free, along with any pre-existing medical conditions. Having to cover my wife's minor pre-existing condition basically ruled out ever living in the USA for us.
Take into account what will insurance be if you have kids, not to mention that even with insurance you will usually still get an invoice after visit to the doctor/hospital (correct me if I am wrong), which may be substantial amount of money (even after insurance negotiations, etc.).
Don't know how it's in US but in EU you have around 20-30 days of payed holidays, payed sick leave, payed _sick child_ leave (!). For example my coworker's 2 kids and wife had severe pneumonia, full treatment took around 2 or 3 months and he could help his family on paid sick leave that whole time. I do not know how much it would've cost in US but it would be a significant amount of money, not to mention that you would still needed either to work, to take unpaid leave or to quit.
It's all about averages. You maybe healthy (now) and do not pay much, but what if some serious illness hits you or your family member? What if you will get some chronic illness/condition? On those cases your insurance price may be adjusted.
To be fair, I want social health care to be more efficient and economical, i.e. not to pay 1/3 of my earned money for it, but I am treating it as a cost for my sanity and not needing to worry about some shit luck hitting me and insurance twisting their ass out of the situation, as insurance's goal is to pay you out as little money as possible.