Let me re-phrase that..."the majority of the deliverers don't really honestly truly care if if anyone listens".
If the publishers really, honestly, truly believed that Armageddon was coming "real soon now", within a matter of weeks or months, and they really believed that people's salvation depended on their response to the preaching efforts, would their presentations really be along the lines of "Good-morning-here's-the-latest-Watchtower-as-you-can-see-it-asks-a-very-interesting-Bible-question-can-I-leave-it-with-you...not-interested-OK-have-a-nice-day."
Of course, there ae a few that really are motivated to want to help people, and are really sincere in their efforts. But in my 40+ years of experience, I think by far the majority are primarily interested in being seen by the elders and/or their peer group as appearing to busy, and really can't wait for the coffee break to start.