Having read a number of comments, both of detractors and supporters, it's worth noting the wording of the proposal: 

An important feature of this proposed change is that no taxpayer dollars
would go to subsidize coverage for these adults. The insured employee
would be responsible for the entire premium for the additional adult,
unlike their own coverage, where the state pays part of the cost of the
insurance on behalf of the employee.
 

Therefore, it's going to cost new participants the full amount of their insurance with nothing from the taxpayer. Many of those oppose this, so they claim, because of cost. They can now be calm, if that's their genuine reason. But for others, this new plan will seem unfair, when compared to marital benefits. And certainly compared what many corporations and states are doing, it is far less. But at least, it's a step in the right direction. It's a matter really of simple fairness, in a system that otherwise rewards groups living as a family.  And one can assert that it will help productivity in Virginia, because it certainly will allow much better recruitment and reduce the incredible stress of having no access to group insurance.