In fact, there is quite a bit of support now for a Massachusetts Constitutional amendment to make marriage between one man and one woman.
The Boston Globe ran a ridiculously skewed poll which showed 50% support for the decision. NPR is probably repeating that as fact.
Once the decision came down, because of the tremendous respect people have for the rule of law, there is respect for the decision that still is out of whack with anything the legislators of Massachusetts would have done or been able to do.
People are inclined to go along with a civil union compromise because it sounds good.