It is over ten years since I knocked on a door with the Watchtower, and probably eleven years since I could be bothered to make an effort. When I was a fresh faced enthusiastic publisher, I would attempt to overcome one conversation stopper, and then leave politely.
My most mortifying field service experience was when accompanied by an elder with the physical presence and charm of Lurch from the Munsters. An elderly lady who obviously was not interested, and did not want to talk to us on her doorstep answered the door. Brother Lurch would not take any polite rebuff for an answer, and the woman became distressed in her efforts to dismiss us. When she finally snapped and slammed the door, he commented "She wasn't very nice, was she?"
In the nearly four years I have lived at my current address, I have had...........one visit from the local JWs. A young woman accompanied by a middle aged man simply displayed the WT and Awake and asked if I would care to read their bible-based magazines. I said that I would not, and they toddled off. Well, there goes my chance for everlasting life! Thank God we aren't being sifted as sheep and goats based on our reaction to that, anymore! Is it any wonder that Joe Public hasn't got a clue what JWs believe?
I think that where there is a more aggressive approach, it is not down to a zeal to save lives, but rather an ingrained contempt for "worldlings". Birdfood doesn't merit manners.