I have no idea.
I could speculate that perhaps it's because you guys are more concerned about him singing from your songbook than considering his stance and record on the issues.
But, I could be wrong.
VCDL doesn't make endorsements - it just surveys candidates on gun rights issues of concern. It makes sense that a gun group would hope to influence direction of gun rights policy.
VCDL does have a PAC that makes endorsements based on past record & survey. The record tends to trump survey answers but I don't think they will endorse a candidate that won't answer a survey.