PSA: Shaming don't work. It didn't work in 1642 for Hester Prynne and it don't work now. Humiliation diminishes. Humiliation fosters defensiveness. And most importantly, humiliation causes people to deny responsibility. How much of your animal activism is rooted in punishment versus creating change? Now be honest.(Note: PSA is an acronym for public service announcement)
I have wrestled with aspects of this over a number of years. By that I mean I have gotten angry and upset and said (and thought) negative things to or about people who dismiss or reject or ridicule veganism. And...that's really a piss poor way to go about getting humans to convert to a vegan lifestyle. I've never had anyone that I behaved poorly toward fall down and say I'm sorry and convert to veganism.
Whereas I've been fortunate enough to have several people over the years be open to listening to my non-shaming, non-attacking message about the harms associated with not living vegan and eventually they opted to live vegan too.
It's vitally important for me (and for you too) to remember that all the people who don't live vegan are going to have to eventually come to living vegan if we are to end systematic human harming of our sister/brother Earthlings. And...it's unlikely to further that goal if we attack or shame or humiliate them. They are potential allies in the quest to stopping the harming of Earthlings who don't happen to be human and beating up on them isn't very wise or effective.
Most of us, at one time, were not living vegan and it's important to remember that too.
I would not have wanted someone who was vegan to have attacked or shamed or humiliated me when I was gripped with obliviousness to the harm I was doing...and no one else wants that either.
The fact is...when we approach people that way they almost always focus on defending themselves...not on listening to the message that might be being conveyed. I'm not saying they'll necessarily listen if you don't attack or shame them...but I am saying they are much more likely to be open to an approach that isn't humiliating toward them.
If you can...pretend that the message you're conveying is being directed to you...if it would offend you then probably someone else would be offended too. Offense usually evokes defense...not receptivity or careful listening.
Christopher said it a lot more concisely and eloquently than I can.