I think it was generally understood by most JWs that the Governing Board members did not go from "house to house" as other members did. The rationale of the time was that they were too busy producing the literature to be able to spend time in this ministry. But I can remember that I had a difficult time to accept this since we were told that the apostles themselves went "from house to house." Were the leaders at Bethel above the apostles?
Of course, later we found out that the term "house to house" really meant "in the homes." ( Compare Acts 5:42 with Acts 2:46) In other words, neither Jesus or the apostles went from house to house as do JWs today. Rather, they taught "in the homes" of interested people. When this explanation caused a slow down in the ministry, the Watchtower quickly reverted back to the old explanation.
One of the early criticisms of Rutherford was from an insider who noted that he sent others forth into the ministry work while he sat back enjoying the luxury of his office.