I always tried to be respectful with the householders when they would indicate their disinterest. I would usually just say something along the lines of "I understand you're busy, have a good day."
The kind of remark reported above is a good indicator of where the org is headed. I've said it before, I'll say it again: The WT is playing an endgame and they know it. "Nice" Witnesses are not going to last long unless the tide turns. And judging by everything I've experienced since I was baptized, it doesn't appear likely. The only folks that will be left after a few more years are the kind of folks that make snarky, disrespectful, rude, intentionally antagonistic comments like the above. Pretty soon it'll be back to the outright hostility and fanaticism of the Rutherford era. It's the only way they can survive without meaningful reform.