For me, it's like flipping a coin. In 50% of the time, my encounters play out like that - or they would play out like that if I was pushing for further discussion. The other 50% people seem to be genuinely interested and ask questions. However, they mostly want to have a conversation but are not in a mental state where they would want to "understand" what I am saying.

On the other hand, I have some training in discussing vegan topics, so I am slightly prepared to not let discussions derail that often.