According to Martin Luther King, Jr. (in The Letter from Birmingham Jail) there are four steps of nonviolent activism:
“In any nonviolent campaign, there are four basic steps: collection of the facts to determine whether injustice exists; negotiations; self-purification; and direct action.”
I think some vegans are just a little too caught up on step three and not concerned enough with step four.
Or, as Erik Marcus wrote:
“just twenty minutes devoted to [vegan] leafletting outweighs the effects of a lifetime of eating at questionably vegan restaurants.”