Yes, exactly this.

It seems reasonable to me to describe laws as "rules that the government acts as if all citizens have agreed to abide by", at least for values of 'acts as if' that apply to the judicial system. The government acting that way results in a system that works reasonably well as far as I can tell, and the fact that the government acts that way makes it generally reasonable to act as if one has agreed to follow those rules. But that's not the same as actually agreeing to follow those rules, and the most rational way of handling the situation is to keep that in mind and actually do a cost/benefit analysis when something illegal seems like it might be worthwhile anyway - and, such a cost/benefit analysis should take all the results of the action into account, including e.g. the possibility of the laws being changed to restrict further behavior of that type, or the possibility of getting a problematically bad reputation, or more subtle issues.