I may be wrong, but I think he probably drew the line in the right place.
“Tillerson successfully urged the Boy Scouts of America to allow gay scouts to participate.”
In other words, he didn’t support gay scoutmasters, but the right of gay scouts to join the organization. I would go further and say that I agree, as long as those scouts do not attempt to seduce other scouts. As long as they keep their being gay to themselves.
According to this article, he led the charge for gay scout leaders: