A leader can be banned for any of these things, or for any other reason, by the unit's sponsoring institution.
Here's an extreme example. A physician who is an abortion provider applies to a unit to become a Scoutmaster. If the sponsor is a Roman Catholic parish, they'd probably say no. If the sponsor is a public school, they might well say yes. It's up to the sponsor.
The determination of whether or not someone is moral enough to be a Scouter is in some very limited cases set by National. In other cases, it's left to the sponsor.
And yet the national office took it upon itself to ban homosexuals as members and leaders for every single chartered troop. Let's take your example. What if troops chartered by Catholic churches demanded that anyone who supported abortion be denied a leadership post in the Boy Scouts? What if they said that children born of people who had divorced and remarried were illegitimate in the eyes of God and should be denied membership? Should the Boy Scout leadership then ban them from membership? Or should they let the local troop make that decision and not force their policies on the rest of the organization? And if the ledership allows individual troops latitude in that then why do they arbitrarily ban men like Mr. Dale?