Generally I would agree, and oppose government intervention to legislate safety and common sense.
I, however, draw the line where children become involved.
I disagree with your approach on two counts.
The first is that my own experience has been that most places do not have adequate ventilation. Depending on the design of a venue, the smoke drifts over to tables where children are seated. The parents have attempted to protect their children, but cannot.
The second is, as you've experienced in your trips to IHOP, parents *won't* always make decisions that are in the best interest of a child.
I view the prohibition of smoking in child-accessible venues the least amount of government intervention to solve the problem.
One option is allowing people to vote with their feet, and parents with children simply refusing to patronize places that permit smoking or fail to have adequate separation and ventilation to spare non-smokers and children from second-hand smoke they don't wish to inhale. Again, your IHOP experience indicates that this would probably not be successful, since there will always be a percentage of families that continue to patronize the locations, contrary to their childrens' best interests.
Another solution would be enacting legislation to require business owners to have adequate ventilation. This creates a significant financial burden to the business owner, and therefore is a solution I cannot support.
A third would be some sort of active enforcement of "smoking sections" that would make it unlawful to permit children to enter [although that still doesn't resolve the above issue of smoke being un-contained].
I don't view smoking as a right. Granted, going to IHOP as a family is not a right, either, but what do we do in cases where children are being endangered through their parent's actions?
Even if smoking *were* a right, as the old adage goes "your right to extend your fist stops at my person". Or in this case, my child's person.
I do feel that, even in the smallest possible government, one of the most crucial roles is to protect its citizenry, ESPECIALLY those unable to protect themselves. In this case, children.